Hi Everyone, The injectors are back in and working properly but this engine STILL isn't running correctly. I go through some more diagnostics and find something! Here we go! (again...) Here is that Fuel Pressure Tester kit: amzn.to/2Y63NQS I did have to modify one of the adapters to make it fit... Just FYI Email if you need more info.
Agreed whole heartedly. I watch a ton of UA-cam videos - which I how I became a UA-cam Certified Mechanic 👨🔧 - and these videos are excellent. I always learn something along the way.
Just a word on yanking a plug wire while it's running.. in a simplistic coil/spark system, the peak voltage is determined by the spark gap. When you remove a plug wire from a plug and don't give it a path to ground, you're spiking that coil field collapse voltage to pretty stupendous levels. If you don't give it a path to ground, it'll find one. Be it through a weak plug wire, through your hand/heart, or through the insulation of the coil itself. So about the fuel pressure gauge footage.. your fuel pressure needle was shown *dipping* during these periods of poor idle. As the air was being purged from your fuel rails, there's less and air serving as a pressure accumulator, and the drop-outs in supply pressure become more noticeable. Could be caused by a mess of things. But at 6:05, it's pretty clear.
If you haven't already done so, I suggest checking the wiring harness for continuity since you have something making an intermittent connection. The connectors are all crimped on at the factory, and by this time one of them maybe breaking where a wire goes into a metal connector somewhere. It's a tedious job. Since the engine has been out, something may have gotten pulled apart internally.
Right around minute 15:10 on your video you show a view of the Motronic ECU while you are removing the DME relay. Over time these have been known to cause issues and I noticed some rust on the mounting bolts which makes me wonder if there has been a history of water sitting in that area which could have got into the ECU as it is not waterproof. You can open it up for a look. They can also suffer with dry solder joints. Love your show. I too have a 3.2 coupe, a G50 '87 one, which I have owned for 26 years. They are great cars.
Yes, great eye. This being a convertible had a leaky top when we bought it. It has since been replaced, but you are correct. I am a little worried about the ECU, but it was running fine (not perfect) before and these symptoms are new. Funny though there isn't any rust on the floor boards. Just the bolts/nuts/screws.... It is a bit odd... Gosh I hope the ECU is good. We'll see. The DME relay is also 20 years old... That is getting replaced as well... I'm just not convinced on the coil...
@@HeidiandFranny I agree about the coil. In fact the old ones are better than the new ones, made in Brazil, which fail all the time. The DME relay is my favourite. I had one suddenly fail while out on the road at some traffic lights, which was embarrassing, but luckily had a spare. These guys do a solid state one which looks interesting. www.ftech9.com/new-products/911-ssr-pp. I also do think its worth having a look inside the ECU. Good luck!
Hello Heidi and Franny's Garage, Another great video and believe you are totally on the right track. Coils, when heated are most likely to show problems. If you let the car cool, it may run fine again and pass the Ohm test. Cannot wait for outcome!......PS: Do you use oscilloscopes yet? With your knowledge and background, believe you would enjoy this tool and now cheap to get for your laptop with recording functions. I purchased a modest 2 channel from Pico (scope only) and have been amazed with its usefulness. Now have added amp clamps and can perform relative compression tests just by running engine with the starter! Good luck, the car/engine is so clean and it showcases your attention to detail! Cheers, Mr. P
Thanks so much! I really do need to up my game with a scope. I have one I used back in the day when I was building filters and amps, but I should drag that thing out to the garage and give it a go. I didn't know how useful they can be but I've been watching some cool videos on it. Love it!
I always changed all the ignition components, right. Down to the battery and alternator on old cars. 35 year old stuff is way beyond best before date, save yourself much time and work. Personally ,since you had the engine removed already , I would’ve pulled the heads and oil pan for inspection . But that’s just me. Great videos though, keep up the excellent work.
I bought a 1989 3.2 Carrera in 2000 and kept it as a daily driver for around 10 or 11 years in the uk, I wish it was now, I’ve learned a lot watching your videos. My DME relay failed one day on the motorway and cost me £300 to get it towed home I kept a spare in the glove box after that.
It's such a pleasure watching you work. Calm and methodical. My 996 is not running quite right and you've inspired me to rake a look at the injectors, I'm sure they're overdue a cleaning!
I had a similar problem years ago with a Lucas coil in an Austin Healey. It worked fine at the beginning of a drive then died. A mechanic told me that they develop cracks within them , and when the coil heats up, the crack will separate the wires in the winding, and no current. Tough to diagnose. Great video, thanks for posting.
Love the methods you use. Process of elimination and good slow pace. Your videos are very informative and truly enjoyable to watch and follow along. Please keep having fun.
Hi from UK, Franny, you have to check the the TPS, Motorinic is a demon on its setting, it is I assume 1986.?, the resistors just wear away, and the fuel shut off, does exactly what yours is doing, check the readings at ECU pins. Best of luck, nice diag.
Your video shoot and editing is superb. I also love how you guys take care of your cars and how neat and tidy it is. You really have the enthusiast mindset.
One of the best electrical Gish tools is an oscilloscope and they are cheaper now that u can scope for connection to a lap top. With a scope you can see the signals very handy. The one thing about new car components is that out of the box some will be faulty and I believe the main reason why mechanics get a cost reduction on new parts. A great video as always and I always learn something here. Thanking you
I does seem like the ignition is dropping out. I would pull the DME and remove the cover. You can see if one of the solder trace(s) is cracked. The fact that you did not have this issue on the last video suggests the DME relay was effected when it was unplugged. The coil is probably in need of replacement is the secondary winding is open but probably still arcing internally to create enough spark.
Superb video. Very thorough and entertaining. I would connect a scope and current clamp to the coil primary windings. The waveform would be pretty informative and should pinpoint if the coil is open/shorted. Minimal or no dismantling needed. Oscilloscope and training may be the next forward step in your evolution.
Absolutely carry a spare DME. I had a 1994 3.8 liter 993 RS. Upgraded by Manthey Racing in Germany. Ran superbly for 2 years... until the coil died. New coil in, driving again.
Hi Franny, I'm in the UK & only recently found these videos. I watched them all practically back to back & absolutely enjoyed them all. I really hope you get this sorted. Johnny Brine.
I'm with MIke Hammer also Vanagon syndrome on youtube. Those air flow matering electrical connectors can corrode into the wire. I love the Carrera. Hope to own one after graduation.
I've an 85 911 and really enjoy your videos which will be very helpful if I need to dive into motor. It's only let me down once and the ecu failed totally. Rather than an intermittent fault like you've had mine was driving perfectly down the road at 80mph then just went totally dead. Hope the coil sorts it
Hi Fran, I experienced a similar problem with a 1963 car. Weak spark, even after replacing the coil all the wires, plugs, cleaning entire fuel system... the fault was eventually diagnosed as due to bad wiring/contact from the ignitionlock to the coil. Might be worth double checking this as well. The contact at the back of the ignitionlock have a direct influence and can cause the engine to stall... good luck and love your patience.
I watch a lot of YT content and the quality of your production and editing is greatly appreciated. In addition the content is extremely informative and highly researched to ensure it is accurate. It would be interesting for a behind the scenes one day to give us an idea of how long it really takes to produce a video of this quality. Keep it coming. Thanks !
Idle switch? Idle air control valve? Get a timing light on it and see what spark is doing? Check all the DME connections to the engine. Have you a CO meter? Fuelling and overal operation doesn’t sound right. Go through all the primary inputs. A new part is not necessarily a *good* part...... Fingers crossed it's the coil but those MAFs don't like being disturbed and also if you have an airleak, that MAF won't compensate for it so a big leak (diagnose by spraying WD/brake cleaner over the manifold and seeing if the engine speed changes) will affect all the cylinders. Good luck! Nice Rattarossa shirt!
Thanks for all that. Yup... I'm not completely convinced the coil is it. I can replace it to rule it out (and it is super old), but yes, lots more to test.
@@HeidiandFranny Looking forward to hearing how you're getting on with it. Engine detective stories are always the best and the most satisfying when they're solved! Loads of gumption added to the project store at that point! (Pirsig had engine projects so well understood sooo many years ago)
Everytime I watch your videos on the 3.2 it motivates me to find and repair the problems with my 1988 BMW 535i and not give up on it. At least my 2019 Porsche is perfect
I had an 86 Carrera (and miss it dearly) that had body work done. When I got the car back, I had all sorts of ignition and charging issues - it turned out some of the grounding wires between the engine and chassis had not been reconnected, resulting in inconsistent/weak grounds! Maybe check ground with the multimeter between engine and chassis/check those grounding wires! Lovely clean engine, I enjoy your process!
Thanks Todd, I was pretty careful to clean all the ground connections, but I will double check. It has to be something I've touched and the grounds do qualify!
Hi, try spray startgas/spray around hose connections, injector gaskets etc, the engine will rew up if it's a leak. You can borrow a smoke machine to detect leaking points. That air meter will measure up and send the info to the ecu, if something is wrong, you'll end up with a harsh idle and rew or even a no start. Testing the exhaust values can get you info about what's going on too.
Morning Heidi and Franny, All the years I’ve worked on hot rods in cars and electrical I think it is the coil so what happens is the resistance in the coil it starts but as the coil starts getting hot the coil breaks down with shuts the engine down so my best guesstimate without looking at the car I think it’s the coil, Paul
This is brilliant. So helpful when you are building a new engine as I am. Definitely masterclass stuff. Many thanks. I have often found that condensors or capacitors are prime culprits for poor running as they can half work. The best video.
@@HeidiandFranny I love your clear technical explanations and your use of diagnostic tools. It is so nice when you get an engine to run sweetly. Sometimes I find baselining each system is the only option. Like remove tank. Acid treat reline and ah the breather is blocked! No wonder it had fuel starvation! Thanks. Hmm do I tackle a Carrera!
If I understood correctly, all of the spark plug wiring has been replaced. If the resistance of the new wiring is too high for the original coil, you will develop a weak spark, then an erratic coil, and, eventually, a fried coil. It sounds like the same progression as you're seeing. Something to consider. Good luck.
I know nothing about cars and engines, but something about your video kept me watching. I liked how you clearly explained your thought process while doing the troubleshooting.
Hi from the UK. a couple of things. secondary dc 800-900 ohms not 8 ohms, worth checking your DVM multimeter is on the correct setting, if it's not an autoscaling type. The secondary coil windings could be failing under spark load, i.e. internal short, if you have been cranking without the spark plugs. I had a cut-out issue on my 1986 3.2, found the ignition switch (key-operated) was fautly due to me over oiling the barrel, the give away was the alternative lamp would occasionally glow, it was back feeding, from the alternator via a poor connection in the ignition key barrel. I understand the igntion coil supply is via the ignition switch not the DME computer. good luck.
Thanks for that. You are correct. Bentley has the spec as "5 - 8.7KOhms" That is a tad misleading (especially if you miss that "K" at the end) but I know what they are getting at. Still, that is a very old coil. I'm not convinced... Lots more to check. Thanks!
Fanny, let a workshop test the coil under tension (they simulate the operating conditions to see if the insulation leaks, this happens after 35 od years or so). If you renew the coil make sure to use fresh hi-tension cables (forgot if you renewed them already). This is a typical case of Murphy's law !! Good luck, Frank (Holland)
That was my thought as well. I would suspect this is an electronic issue but a load test would be advisable. Unfortunately it might cost as much to replace the coil as to have it tested. (As much as I don't like throwing parts at an issue)
Seems pretty conclusive to me, we know you have fuel pressure and the injectors are firing and ok, and we know you have good compression so that really only leaves something related to spark. Its pretty impressive really that the coil has lasted for 36 years!
Another great episode Heidi and Franny, it clearly shows the logical process you are going through to analyse and eliminate the possible causes of the engine issues you are encountering. Thank you and keep at it ❤️💙
Nice episode thanks. I've seen this before with cars that have been off the road for a while. Random things start failing! With my Land Rover, it was fuel lines, fine when I started my engine rebuild, 8 weeks later, they had all started leaking!
I,m always impressed how you deal with all the problems, how you stay calm and how you analyze things. Great inspiration throughout all your videos. Good luck with the car, I,m sure you,ll bring it back to run as it should🤞👍
Yes, this is a cliffhanger! Really enjoy your approach to troubleshooting. I’ve been an aircraft mechanic for 35 years and I own a German car from ‘89, and a bunch of other old cars, boats and motorcycles. Your systematic technique is spot on.... I took a one week aviation tech course called “white glove troubleshooting” where the technique was to diagnose the problem based on system knowledge. It’s a very accurate technique and it looks like you are following that process nicely.
Oh, that sounds really fun! I like that. I think it is important to understand what you are looking at :) I don't always get it right but I am learning a ton!
Hi, i had similar stalling on my e39 530i, it was the idle control valve. You had it already out and it was moving, but you did not lubed it. Its possible that if you take it out it wont move free instantly. Just shake it, lube it and shake again and it will run like a champ.
This Carrera is really putting up a fight, but it will be tamed eventually! I wish the 'professional' technicians at the dealership I use would check components and diagnose problems the way you do. Very impressive! That coil definitely looks suspicious, but kudos to Bosch for making it last this long. It's older than most UA-camrs!
Those Bosch coils are pretty reliable. I’ve got a ‘85 928S and it uses two of them. One of mine cracked and leaked the oil out and the coil still worked. With that said, it’s 36 years old, you’ve got weak spark, and if you can find a good price might as well knock it out. I don’t think I have a DME relay on mine. I think some of the earlier ones do. That hose clamp is not necessary on that vacuum elbow.
Franny, your ways stay so calm when a problem arrises and calmly try to figure it out. I be going crazy. Sometimes I try and fix engine things on my cars to and sometimes I just go NUTS!
My first thought was the DME relay. Interesting diagnostic on the coil. I’ve often wondered how to test one. Personally I’ve been too worried about getting some sort of voltage shock so I stay away from them. Haha
I think you approached the case the right way, very likely that the coil is faulty, well they are not expensive, so if you replaced them and you keep the problem I would look at the transistor circuit of the ignition, it is known that you can suffer that the solder connections of the circuit board after all those years sometimes become bad, and the DME relays of course
Great video on a vexing issue. The way it dies after revving initially made me think fuel problem, but you’ve done enough testing there to move on. Whenever I suspected a coil I’ve replaced them since it’s a cheap fix, but they never proved to be the issue. I’ve seen a lot of good comments about checking the DME and Motronic controls along w/ O2 sensor. That is a good start for next steps. Especially since there is evidence of possible water damage in that area. Someone leaves a convertible top down and it rains....... not good for electronics located under the seat.
Right. I have my eye on the DME relay, but I need to test it. I have a new one coming I can use as a spare. I'm going to go through the service manual's procedures to check everything. It is perplexing. Seems like it should be something I touched though...
@@HeidiandFranny This is the opposite of a “well sorted” car so it’s actually beneficial to go thru all the systems. You’ll know this car extremely well once it’s done ;-). I always used the Chilton manuals on my older 911’s (and The Idiots Guide for my VW’s.). Haynes was especially useful for my e30 BMW 325 and e24 635 and those are the most contemporary to your 911. I never found the factory manual to be that helpful for troubleshooting my 84 911. They just assumed to much inherent knowledge on the part of the mechanic i guess. Just keep the faith (as John Muir would have said) amd you’ll get it figured out!
Hi Franny and Heidi! I recently happened across your channel and I am so glad I did. I love the way you work through your car's issues; so calmly and intellectually. Well done, you. Thank you for bringing us along on your journey.
Oh no the injectors didn’t fix it. Your master tech skills and diagnostic flow is amazing. You’ll figure it out. I don’t know what type of air intake gasket is on there but it could be damaged and sucking in air. Is it also possible that the speed sensor tone ring teeth could be damaged. Can wait to see what you find.
I own a 1992 R129 with an M104. Some 15 years ago, the M104.98 started dying almost every time prior to reaching its regular temperature. Once at 90C it stops dying. We have changed literally everything related to fuel and ignition which cost me something between 5k and 10k € to date. Eventually I gave up ie I accepted the engine dying when its cold. I mention all this as the electronic stuff is pretty much from Bosch too. After all the car is still in mint condition. Even speaking German to the engine failed to prove a rainmaker. So good luck from Frankfurt Germany.
Oh my... Sounds like there has to be something... Sometimes even new parts aren't always good. I had someone comment that the pins in one of the connectors had pushed back into the harness and even though the connector snapped it, the pins weren't making contact. Now that would be hard to trace! Good luck with your car. I hope you find the issue.
TPS confusing computer and ICV cycling. Real smart of u to first eliminate fuel pressure. Am not ruling out 02 sensor circuit. Was fine when it was cold and o2 is disregarded because it was in warm up mode. Then after a few minutes engine stalls just as ecu goes closed loop with a now warm o2 sensor.
Great point! I want to order a new one of those as well. I hear they are a bit fragile. I may have damaged it at one point. I can test it - it is on the list.
@@HeidiandFranny Yours is a 3 wire. I've had a bunch of luck w super cheepo fleabay sensors. Splicing the wires might be an issue. Remember that any combusted silicon immediately destroys the sensor. On assembly make sure that zero antisieze for the thread gets into the sensor tip. I have tested them by disconnecting the signal wire w cold engine, starting and seeing if voltage rises. Alternately bench test by applying 12 vdc to heater wires, wait a minute and shoot some unburned propane onto the tip. Good luck. My 76 911s' cis injection is worn out completely.
Coincidences happen I guess? I initially thought Air-Mass sensor, they do wear out, I don't think this is a hot-wire setup so it's a vane and it constantly flutters while acting as a "pot" and wares out the track......but as ever your knowledge and logical approach will win the day......can't wait for that new coil. You are an amazing, honest, mechanic. Keep up the good work, respect from the UK mate x.
Thanks so much! I'm not a big fan of coincidences either... Not sure I buy it. We are having a bit of cold (and soon to be wet) weather so I hope to get back before the end of the week. Yes the air flow sensor is the resistive type. That is next on the list!
Electronic components can be weird. Sometimes they are fine until taken out of regular service. Then internal solder connections or other bits degrade seemingly without cause. Considering the age of the coil I would replace it even if it tested ok as it's failure would seem likely in the near future.
Hi Franny, really enjoying these videos! My guess was on something electrical as I was watching. Great FA work! Hopefully it’s not something *else* electrical that made the coil wires melt and open. 🤞🤞 You are super patient! I may or may not have thrown the coil to the wall 😂 Anyway, looking forward to seeing your progress with this issue. Gotta say it’s like a really good network tv series and you just have to wait for next week’s episode! All the best to you and Heidi 🙂
I just watched first video and wrote this reply... "With a stethoscope you can hear if the injector is clicking. And how did you remove the sparkplug wire without getting zapped? I have not quite finished the video. The spark did not appear strong" Now I will watch part 2
Snap on coil tester,... generates a spark and one can tell if its strong enough by increasing the gap until it fails to jump. I'd post a pic but i lent it and was never returned. Worked great and very simple. Think it's basically a Ruhmkorff coil. Side note, the guy wanted it to start his pulse jet, and worked for that.
First thing I would do is ditch those plugs and get the OE spec, likely NGK BPR6ES and gap them to spec. You also didn't show the porcelain of the plug, which could have a hairline crack and be your issue. Next is to get it together and let it idle! Do not rev it, no loads, restart it if it dies and let it sit and idle! It needs to relearn the parameters all over again. At the Porsche shop, we would have at least 1-2 of these come in during the Spring running poorly, and would just let it idle for 10-15min. and it would clear right up. If it doesn't clear up, unplug the air flow meter and see if that helps. With it unplugged, it basically reverts to a set base fuel map and will bypass a lot of inputs, but will also run better while having a vacuuum leak, so don't go replacing it right away if it smooths out. I also check the distributor cap to check that rotor and contact are good to go. You should've used the spark tester with the plug installed to make sure you were getting solid consistent spark through the sight glass instead of relying it to ground to 1 of the 4 prongs in the plug which was harder to see. Again, that ignition system was not designed to drive that type of plug and have seen them cause so much more harm than good, including induced feedback into the electrical system in one case study I have seen.
firstly, i enjoy your videos, and i have to say, you are a very good and thourough technician. i have a VERY similar issue with my 1985 euro bmw 635. i have brought it to 3 shops, who couldn't fix it. in fact one of those shops told me that there hasnt been one car in 35 years that they couldn't fix............well, i thought about the high idle, and abrupt power cutoff on deceleration. first thing i checked was the plugs because i had a feeling it was running lean, and sure enough they were white. apparently, none of the shops even checked that. so i looked over and over for vacuum leaks and found none. i found the aic to be bad, a kinked fuel line at the pump, and a messed up air flow meter. it now runs better, but still idles at around 1100 and the fuel virtually shuts off unless you are accelerating. i havent touched the injectors, but after watching your last video, i might replace all 6 and do the lines clips and etc. TY for your great video, but id go back and check for vacuum leaks and a faulty aic!
@@HeidiandFranny well i have to laugh as 3 shops apparently didnt even pull the plugs! pretty sad that there are so few "mechanics" anymore! they plug in a scanner and change parts! thats why i love your analysis of issues...........a true "technician"
Hi Franny! I don't think you needed to send those injectors in at all. I just saw Ian Tyrrell in England try to tune a v12 Jaguar engine and found a few injectors not firing. He simply zapped them with 12 volts from a battery and kept doing that till they unstuck. He said to just zap them but don't leave them hooked up because then you will burn them out. He said they will stick if left to sit for a while. That seems to have been all that was wrong with yours since you left them sit for a year. His UA-cam channel is Tyrrells Work Shop. He's like the pope of exotic cars. Lol I thought sure you had a clogged fuel filter or line. I'm glad you tested the coil. That is pretty old.
I love watching Ian! The way he can tune a carb by ear is amazing :) I have seen that method to unstick them. RC said they would go back through them at no charge and they flow test them as well. They Are much smoother... At $300 a pop I didn't want to damage them.
Blast! I was sure the injectors would do it. Even though I want the engine to run as much as you do you are providing a very useful diagnosis tutorial! I have every confidence in you sorting this.
I had 2 Bosch coils fail intermittently like that back in the day, so I would not be surprised. Fuel pump relay? Yes, carried one around for about 5 years until I needed it. When it dies there is nothing intermittent about it - game over.
Since you had alot of the car apart you might want to check the grounds on the ignition system and coil. A bad ground will give a phantom temp related issues. I chased one on a 530i BMW after I had the motor out, it ended up being a body ground that been painted and not cleaned well on assembly. Good luck on your hunt what ever it turns out to be.
Thanks for that. There are two main grounds - one between the car and the transmission and the other on the intake manifold. Both were cleaned thoroughly and re-installed. BUT, It would be a good thing to re-check them.
@@HeidiandFranny I've seen some coments on the airflow meter and it kinda jared my memory back to my Benz and BMW tech days, those were a royal pain. The potentometer in the airflow meter could develop dead spots or the vane itself could become sticky both could be temp dependant. The vane can sometimes be freed up with some light oil and the continuity of the potentiometer can be checked I beleive but, I'm sorry, I can't remember what connector pins to test at. Hope that is some help to you. I don't want to be the person who "knows" what your problem is just offering some suggestions.
Hi Franny I noticed in the last video when you were using the spark plug tester that the spark was not fast/constant - it was slow/ intermittent. That tester should light up like an Xmas tree with solid spark.
Should be good to test flow of fuel pump. At idle it might give enough flow, but not under load. Looks like fuel pump or pressure regulator is acting up. To check DME relay, normally relays can be bypassed by using wire connected.
I enjoy watching yor videos. Back to basics is what I put alot of faith in. Hopefully the plug wires are correctly attached. Is the firing order correct? 1-6-2-4-3-5 from what I recall. When you had the seat lifted for the DME relsy I saw rusted studs and bolts. This is an environment for bad grounding. All grounds on the chassis need to be examined. Looks like your coil may be bad. If you were cranking the engine with spark wires disconnected and not grounded it is murder on the coil. Hopefully that’s what it is. My 2 cents worth.
Hi Everyone, The injectors are back in and working properly but this engine STILL isn't running correctly. I go through some more diagnostics and find something! Here we go! (again...)
Here is that Fuel Pressure Tester kit: amzn.to/2Y63NQS
I did have to modify one of the adapters to make it fit... Just FYI Email if you need more info.
a really great journey into the best of the past.
Heidi is nice. However, Franny is an absolute star.
That’s a bummer. Hopefully you don’t have to pull the engine again...
@@watchfan6180 totally! Heidi
Why does this young lady not have a million subscribers? She is very good at this....cars and video.
Agreed whole heartedly. I watch a ton of UA-cam videos - which I how I became a UA-cam Certified Mechanic 👨🔧 - and these videos are excellent. I always learn something along the way.
She needs her own show on tv.
Amen, great knowledge, explained well and great camera work and edit. Top class stuff.
Like, Share and subscribe.
Thanks so much Tony!
Just a word on yanking a plug wire while it's running.. in a simplistic coil/spark system, the peak voltage is determined by the spark gap. When you remove a plug wire from a plug and don't give it a path to ground, you're spiking that coil field collapse voltage to pretty stupendous levels. If you don't give it a path to ground, it'll find one. Be it through a weak plug wire, through your hand/heart, or through the insulation of the coil itself.
So about the fuel pressure gauge footage.. your fuel pressure needle was shown *dipping* during these periods of poor idle. As the air was being purged from your fuel rails, there's less and air serving as a pressure accumulator, and the drop-outs in supply pressure become more noticeable. Could be caused by a mess of things. But at 6:05, it's pretty clear.
Your demeanor and patience is priceless. Great work!
Thanks so much!
You have the patience of a saint. :)
If you haven't already done so, I suggest checking the wiring harness for continuity since you have something making an intermittent connection. The connectors are all crimped on at the factory, and by this time one of them maybe breaking where a wire goes into a metal connector somewhere. It's a tedious job. Since the engine has been out, something may have gotten pulled apart internally.
Great point! That wire is old and stiff. I did try to be careful, but you are very right.
Right around minute 15:10 on your video you show a view of the Motronic ECU while you are removing the DME relay. Over time these have been known to cause issues and I noticed some rust on the mounting bolts which makes me wonder if there has been a history of water sitting in that area which could have got into the ECU as it is not waterproof. You can open it up for a look. They can also suffer with dry solder joints. Love your show. I too have a 3.2 coupe, a G50 '87 one, which I have owned for 26 years. They are great cars.
Yes, great eye. This being a convertible had a leaky top when we bought it. It has since been replaced, but you are correct. I am a little worried about the ECU, but it was running fine (not perfect) before and these symptoms are new. Funny though there isn't any rust on the floor boards. Just the bolts/nuts/screws.... It is a bit odd... Gosh I hope the ECU is good. We'll see. The DME relay is also 20 years old... That is getting replaced as well... I'm just not convinced on the coil...
@@HeidiandFranny I agree about the coil. In fact the old ones are better than the new ones, made in Brazil, which fail all the time. The DME relay is my favourite. I had one suddenly fail while out on the road at some traffic lights, which was embarrassing, but luckily had a spare. These guys do a solid state one which looks interesting. www.ftech9.com/new-products/911-ssr-pp. I also do think its worth having a look inside the ECU. Good luck!
Hello Heidi and Franny's Garage,
Another great video and believe you are totally on the right track. Coils, when heated are most likely to show problems. If you let the car cool, it may run fine again and pass the Ohm test.
Cannot wait for outcome!......PS: Do you use oscilloscopes yet? With your knowledge and background, believe you would enjoy this tool and now cheap to get for your laptop with recording functions. I purchased a modest 2 channel from Pico (scope only) and have been amazed with its usefulness. Now have added amp clamps and can perform relative compression tests just by running engine with the starter!
Good luck, the car/engine is so clean and it showcases your attention to detail!
Cheers,
Mr. P
Thanks so much! I really do need to up my game with a scope. I have one I used back in the day when I was building filters and amps, but I should drag that thing out to the garage and give it a go. I didn't know how useful they can be but I've been watching some cool videos on it. Love it!
I always changed all the ignition components, right. Down to the battery and alternator on old cars.
35 year old stuff is way beyond best before date, save yourself much time and work.
Personally ,since you had the engine removed already , I would’ve pulled the heads and oil pan for inspection .
But that’s just me.
Great videos though, keep up the excellent work.
Love the systematic diagnosis. Hopefully it is one of those 2 things so you are not still scratching your head.
Thanks Jeff! It is giving me a run...
I bought a 1989 3.2 Carrera in 2000 and kept it as a daily driver for around 10 or 11 years in the uk, I wish it was now, I’ve learned a lot watching your videos. My DME relay failed one day on the motorway and cost me £300 to get it towed home I kept a spare in the glove box after that.
Thanks. That is great advice.
It's such a pleasure watching you work. Calm and methodical. My 996 is not running quite right and you've inspired me to rake a look at the injectors, I'm sure they're overdue a cleaning!
Franny is like the nicest person I have ever Met/watched on the internet.
Why thank you!
I had a similar problem years ago with a Lucas coil in an Austin Healey. It worked fine at the beginning of a drive then died. A mechanic told me that they develop cracks within them , and when the coil heats up, the crack will separate the wires in the winding, and no current. Tough to diagnose. Great video, thanks for posting.
Good to know!
Love the methods you use. Process of elimination and good slow pace. Your videos are very informative and truly enjoyable to watch and follow along. Please keep having fun.
Thanks so much!
Loving your diagnostic process
Thanks!
Franny, you're like a calm tutor drying my tears helping me with my math homework after I tried alone and failed haha
LOL! might need someone to dry my tears if I can't figure this out ;) ...also, math homework...
Hi from UK, Franny, you have to check the the TPS, Motorinic is a demon on its setting, it is I assume 1986.?, the resistors just wear away, and the fuel shut off, does exactly what yours is doing, check the readings at ECU pins. Best of luck, nice diag.
Thanks so much for that! It is next on the list. Good idea to check back at the ECU.
Your video shoot and editing is superb. I also love how you guys take care of your cars and how neat and tidy it is. You really have the enthusiast mindset.
Thanks so much!
One of the best electrical Gish tools is an oscilloscope and they are cheaper now that u can scope for connection to a lap top. With a scope you can see the signals very handy. The one thing about new car components is that out of the box some will be faulty and I believe the main reason why mechanics get a cost reduction on new parts. A great video as always and I always learn something here. Thanking you
Thanks Franny . I have similar issues on a 1977 MBenz W123 280 E . This is very helpful .
I does seem like the ignition is dropping out. I would pull the DME and remove the cover. You can see if one of the solder trace(s) is cracked. The fact that you did not have this issue on the last video suggests the DME relay was effected when it was unplugged. The coil is probably in need of replacement is the secondary winding is open but probably still arcing internally to create enough spark.
Superb video. Very thorough and entertaining. I would connect a scope and current clamp to the coil primary windings. The waveform would be pretty informative and should pinpoint if the coil is open/shorted. Minimal or no dismantling needed. Oscilloscope and training may be the next forward step in your evolution.
Absolutely carry a spare DME. I had a 1994 3.8 liter 993 RS. Upgraded by Manthey Racing in Germany. Ran superbly for 2 years... until the coil died. New coil in, driving again.
Hi Franny, I'm in the UK & only recently found these videos. I watched them all practically back to back & absolutely enjoyed them all. I really hope you get this sorted.
Johnny Brine.
Thanks so much Johnny! We'll get it!
I'm with MIke Hammer also Vanagon syndrome on youtube. Those air flow matering electrical connectors can corrode into the wire. I love the Carrera. Hope to own one after graduation.
I've an 85 911 and really enjoy your videos which will be very helpful if I need to dive into motor. It's only let me down once and the ecu failed totally. Rather than an intermittent fault like you've had mine was driving perfectly down the road at 80mph then just went totally dead. Hope the coil sorts it
Hi Fran, I experienced a similar problem with a 1963 car. Weak spark, even after replacing the coil all the wires, plugs, cleaning entire fuel system... the fault was eventually diagnosed as due to bad wiring/contact from the ignitionlock to the coil. Might be worth double checking this as well. The contact at the back of the ignitionlock have a direct influence and can cause the engine to stall... good luck and love your patience.
Thanks, I'm pretty sure the signal to the coil comes from the ECU. We'll get it though!
Franny I’m a big fan of yours, you make all the car projects really fun and simple👍🏼
Thanks so much!
Thank you for making us understand how these cars function and how to work on them!
Yea! Thanks!
I watch a lot of YT content and the quality of your production and editing is greatly appreciated. In addition the content is extremely informative and highly researched to ensure it is accurate. It would be interesting for a behind the scenes one day to give us an idea of how long it really takes to produce a video of this quality. Keep it coming. Thanks !
Thanks so much!! It takes most of the day to film, and editing is several days/evenings. Then there is the prep work and research. But it is fun!
Idle switch? Idle air control valve? Get a timing light on it and see what spark is doing? Check all the DME connections to the engine. Have you a CO meter? Fuelling and overal operation doesn’t sound right. Go through all the primary inputs. A new part is not necessarily a *good* part...... Fingers crossed it's the coil but those MAFs don't like being disturbed and also if you have an airleak, that MAF won't compensate for it so a big leak (diagnose by spraying WD/brake cleaner over the manifold and seeing if the engine speed changes) will affect all the cylinders. Good luck! Nice Rattarossa shirt!
Thanks for all that. Yup... I'm not completely convinced the coil is it. I can replace it to rule it out (and it is super old), but yes, lots more to test.
@@HeidiandFranny Looking forward to hearing how you're getting on with it. Engine detective stories are always the best and the most satisfying when they're solved! Loads of gumption added to the project store at that point! (Pirsig had engine projects so well understood sooo many years ago)
Everytime I watch your videos on the 3.2 it motivates me to find and repair the problems with my 1988 BMW 535i and not give up on it. At least my 2019 Porsche is perfect
That '88 535i is awesome! I hope you get it sorted.
I had an 86 Carrera (and miss it dearly) that had body work done. When I got the car back, I had all sorts of ignition and charging issues - it turned out some of the grounding wires between the engine and chassis had not been reconnected, resulting in inconsistent/weak grounds! Maybe check ground with the multimeter between engine and chassis/check those grounding wires! Lovely clean engine, I enjoy your process!
Thanks Todd, I was pretty careful to clean all the ground connections, but I will double check. It has to be something I've touched and the grounds do qualify!
Hi, try spray startgas/spray around hose connections, injector gaskets etc, the engine will rew up if it's a leak. You can borrow a smoke machine to detect leaking points.
That air meter will measure up and send the info to the ecu, if something is wrong, you'll end up with a harsh idle and rew or even a no start.
Testing the exhaust values can get you info about what's going on too.
Thanks for that!
Morning Heidi and Franny, All the years I’ve worked on hot rods in cars and electrical I think it is the coil so what happens is the resistance in the coil it starts but as the coil starts getting hot the coil breaks down with shuts the engine down so my best guesstimate without looking at the car I think it’s the coil, Paul
Thanks Paul. We have a new one on order. We'll see :)
This is brilliant. So helpful when you are building a new engine as I am. Definitely masterclass stuff. Many thanks. I have often found that condensors or capacitors are prime culprits for poor running as they can half work. The best video.
Oh my gosh... I had a series of bad condensers on the 356. New parts too...
@@HeidiandFranny I love your clear technical explanations and your use of diagnostic tools. It is so nice when you get an engine to run sweetly. Sometimes I find baselining each system is the only option. Like remove tank. Acid treat reline and ah the breather is blocked! No wonder it had fuel starvation! Thanks. Hmm do I tackle a Carrera!
If I understood correctly, all of the spark plug wiring has been replaced. If the resistance of the new wiring is too high for the original coil, you will develop a weak spark, then an erratic coil, and, eventually, a fried coil. It sounds like the same progression as you're seeing. Something to consider. Good luck.
DME relay is where I would start. When they fail, they can cause all kinds of weird issues. I keep a spare with me. Good luck!!
...and this one is almost 20 years old... I'll order a spare.
Consider a solid state one from F9T? I’ve had my original and spare fail on a road trip.. sigh. great series, I’ve learned so much, thank you!
@@xlbracing I was wondering the same...
I know nothing about cars and engines, but something about your video kept me watching. I liked how you clearly explained your thought process while doing the troubleshooting.
Thanks!
Very refreshing video. You’re smart and witty, love the “hmmmm and holy cow!” Keep up with the great work.
Hi from the UK. a couple of things. secondary dc 800-900 ohms not 8 ohms, worth checking your DVM multimeter is on the correct setting, if it's not an autoscaling type. The secondary coil windings could be failing under spark load, i.e. internal short, if you have been cranking without the spark plugs. I had a cut-out issue on my 1986 3.2, found the ignition switch (key-operated) was fautly due to me over oiling the barrel, the give away was the alternative lamp would occasionally glow, it was back feeding, from the alternator via a poor connection in the ignition key barrel. I understand the igntion coil supply is via the ignition switch not the DME computer. good luck.
Thanks for that. You are correct. Bentley has the spec as "5 - 8.7KOhms" That is a tad misleading (especially if you miss that "K" at the end) but I know what they are getting at. Still, that is a very old coil. I'm not convinced... Lots more to check. Thanks!
What a great way to learn car mechanics.
Fanny, let a workshop test the coil under tension (they simulate the operating conditions to see if the insulation leaks, this happens after 35 od years or so). If you renew the coil make sure to use fresh hi-tension cables (forgot if you renewed them already). This is a typical case of Murphy's law !! Good luck, Frank (Holland)
Thanks so much! Ya know, I thing there might be a shop here with a coil tester. That is a great idea. I'll look into that.
That was my thought as well. I would suspect this is an electronic issue but a load test would be advisable. Unfortunately it might cost as much to replace the coil as to have it tested. (As much as I don't like throwing parts at an issue)
Seems pretty conclusive to me, we know you have fuel pressure and the injectors are firing and ok, and we know you have good compression so that really only leaves something related to spark. Its pretty impressive really that the coil has lasted for 36 years!
how do we know the compression is good? did she measured it? on cilinder 5?
@@clanpimp #5 was brought to life with the fixed injector in the last episode, so no need to think its compression some will say!
Your a super star 💫 you will get it sorted. Loving this series.
Thanks so much!
This is really really interesting!!
You're slowly building your subscriber base, 50k will a real milestone and well deserved! Keep up the good work!
Thanks so much!! We'll get there :)
Another great episode Heidi and Franny, it clearly shows the logical process you are going through to analyse and eliminate the possible causes of the engine issues you are encountering. Thank you and keep at it ❤️💙
Nice episode thanks. I've seen this before with cars that have been off the road for a while. Random things start failing! With my Land Rover, it was fuel lines, fine when I started my engine rebuild, 8 weeks later, they had all started leaking!
Fantastic video and great fault finding.
Love your videos they are so educational and also fun.
Thanks so much!
I,m always impressed how you deal with all the problems, how you stay calm and how you analyze things. Great inspiration throughout all your videos. Good luck with the car, I,m sure you,ll bring it back to run as it should🤞👍
Thanks so much!
Yes, this is a cliffhanger!
Really enjoy your approach to troubleshooting. I’ve been an aircraft mechanic for 35 years and I own a German car from ‘89, and a bunch of other old cars, boats and motorcycles. Your systematic technique is spot on....
I took a one week aviation tech course called “white glove troubleshooting” where the technique was to diagnose the problem based on system knowledge. It’s a very accurate technique and it looks like you are following that process nicely.
Oh, that sounds really fun! I like that. I think it is important to understand what you are looking at :) I don't always get it right but I am learning a ton!
Hello from the UK. Great video. Love the methodical thinking. Fascinating. :-) Looking forward to the next update.
Thanks so much!
I absolutely love the way you troubleshoot every single aspect thank you. Having the same model it’s really instructional.
Great to hear :)
Hi, i had similar stalling on my e39 530i, it was the idle control valve. You had it already out and it was moving, but you did not lubed it. Its possible that if you take it out it wont move free instantly. Just shake it, lube it and shake again and it will run like a champ.
This Carrera is really putting up a fight, but it will be tamed eventually! I wish the 'professional' technicians at the dealership I use would check components and diagnose problems the way you do. Very impressive! That coil definitely looks suspicious, but kudos to Bosch for making it last this long. It's older than most UA-camrs!
So the car run better with bad injectors, new injectors maybe found the next weak link in the engine. great content and straight to the point.
Thanks! Actually it is running smoother... I think we have a couple issues at play...
Those Bosch coils are pretty reliable. I’ve got a ‘85 928S and it uses two of them. One of mine cracked and leaked the oil out and the coil still worked. With that said, it’s 36 years old, you’ve got weak spark, and if you can find a good price might as well knock it out. I don’t think I have a DME relay on mine. I think some of the earlier ones do. That hose clamp is not necessary on that vacuum elbow.
It is a Porche even it is an old one. I never saw it in my entire life. But I learn much your logic as you searched the problem.😊👍👍👍
Very nice update. Great to know what to expect from Porsche.
We'll get it sorted :)
Great diagnosis Franny !
Thanks!
This is reminiscent of "Who Shot JR". I'm watching and waiting to see and hear this car run and I have to wait until another vlog comes out!!!
Franny, your ways stay so calm when a problem arrises and calmly try to figure it out. I be going crazy. Sometimes I try and fix engine things on my cars to and sometimes I just go NUTS!
My first thought was the DME relay. Interesting diagnostic on the coil. I’ve often wondered how to test one. Personally I’ve been too worried about getting some sort of voltage shock so I stay away from them. Haha
Thanks! That DME will get replaced. I'll do a follow up, but I misread the spec on the coil resistance. I still want to get it checked out...
I think you approached the case the right way, very likely that the coil is faulty, well they are not expensive, so if you replaced them and you keep the problem I would look at the transistor circuit of the ignition, it is known that you can suffer that the solder connections of the circuit board after all those years sometimes become bad, and the DME relays of course
Thanks for that. I have heard that solder breaks can happen. Let's hope it isn't that :)
Great video on a vexing issue. The way it dies after revving initially made me think fuel problem, but you’ve done enough testing there to move on. Whenever I suspected a coil I’ve replaced them since it’s a cheap fix, but they never proved to be the issue. I’ve seen a lot of good comments about checking the DME and Motronic controls along w/ O2 sensor. That is a good start for next steps. Especially since there is evidence of possible water damage in that area. Someone leaves a convertible top down and it rains....... not good for electronics located under the seat.
Right. I have my eye on the DME relay, but I need to test it. I have a new one coming I can use as a spare. I'm going to go through the service manual's procedures to check everything. It is perplexing. Seems like it should be something I touched though...
@@HeidiandFranny This is the opposite of a “well sorted” car so it’s actually beneficial to go thru all the systems. You’ll know this car extremely well once it’s done ;-). I always used the Chilton manuals on my older 911’s (and The Idiots Guide for my VW’s.). Haynes was especially useful for my e30 BMW 325 and e24 635 and those are the most contemporary to your 911. I never found the factory manual to be that helpful for troubleshooting my 84 911. They just assumed to much inherent knowledge on the part of the mechanic i guess. Just keep the faith (as John Muir would have said) amd you’ll get it figured out!
I believe you nailed the issue with the coil.
That would be great if that is it.
Hi Franny and Heidi! I recently happened across your channel and I am so glad I did. I love the way you work through your car's issues; so calmly and intellectually. Well done, you.
Thank you for bringing us along on your journey.
Thanks so much and welcome!
Your mad diagnostic skills always blow me away. I'm confident your next episode will show this beauty smoothly going down the road.
Thanks so much!
One of the best builds on UA-cam right now, great video
Thanks so much!!
@@HeidiandFranny no Thank You!
Oh no the injectors didn’t fix it. Your master tech skills and diagnostic flow is amazing. You’ll figure it out. I don’t know what type of air intake gasket is on there but it could be damaged and sucking in air. Is it also possible that the speed sensor tone ring teeth could be damaged. Can wait to see what you find.
I own a 1992 R129 with an M104. Some 15 years ago, the M104.98 started dying almost every time prior to reaching its regular temperature. Once at 90C it stops dying. We have changed literally everything related to fuel and ignition which cost me something between 5k and 10k € to date. Eventually I gave up ie I accepted the engine dying when its cold. I mention all this as the electronic stuff is pretty much from Bosch too. After all the car is still in mint condition. Even speaking German to the engine failed to prove a rainmaker. So good luck from Frankfurt Germany.
Oh my... Sounds like there has to be something... Sometimes even new parts aren't always good. I had someone comment that the pins in one of the connectors had pushed back into the harness and even though the connector snapped it, the pins weren't making contact. Now that would be hard to trace! Good luck with your car. I hope you find the issue.
From Puerto Rico, thank you so much for the details. Now i know what to fo with the injectors. 👍👍👍👍👍👍
TPS confusing computer and ICV cycling. Real smart of u to first eliminate fuel pressure. Am not ruling out 02 sensor circuit. Was fine when it was cold and o2 is disregarded because it was in warm up mode. Then after a few minutes engine stalls just as ecu goes closed loop with a now warm o2 sensor.
Great point! I want to order a new one of those as well. I hear they are a bit fragile. I may have damaged it at one point. I can test it - it is on the list.
@@HeidiandFranny Yours is a 3 wire. I've had a bunch of luck w super cheepo fleabay sensors. Splicing the wires might be an issue. Remember that any combusted silicon immediately destroys the sensor. On assembly make sure that zero antisieze for the thread gets into the sensor tip. I have tested them by disconnecting the signal wire w cold engine, starting and seeing if voltage rises. Alternately bench test by applying 12 vdc to heater wires, wait a minute and shoot some unburned propane onto the tip. Good luck. My 76 911s' cis injection is worn out completely.
Coincidences happen I guess? I initially thought Air-Mass sensor, they do wear out, I don't think this is a hot-wire setup so it's a vane and it constantly flutters while acting as a "pot" and wares out the track......but as ever your knowledge and logical approach will win the day......can't wait for that new coil. You are an amazing, honest, mechanic. Keep up the good work, respect from the UK mate x.
Thanks so much! I'm not a big fan of coincidences either... Not sure I buy it. We are having a bit of cold (and soon to be wet) weather so I hope to get back before the end of the week. Yes the air flow sensor is the resistive type. That is next on the list!
Electronic components can be weird. Sometimes they are fine until taken out of regular service. Then internal solder connections or other bits degrade seemingly without cause. Considering the age of the coil I would replace it even if it tested ok as it's failure would seem likely in the near future.
Hi Franny, really enjoying these videos! My guess was on something electrical as I was watching. Great FA work! Hopefully it’s not something *else* electrical that made the coil wires melt and open. 🤞🤞 You are super patient! I may or may not have thrown the coil to the wall 😂 Anyway, looking forward to seeing your progress with this issue. Gotta say it’s like a really good network tv series and you just have to wait for next week’s episode! All the best to you and Heidi 🙂
Thanks so much!
Thorough troubleshooting and you're getting closer to the answer…I just need to keep watching to find out what that was! :)
I really like your channel since you really work on cars and not just put some wheels or stickers as many car youtubers do. Great job 👏
Thanks so much!
Newbie watcher here. Great diagnosis and I'm looking forward to seeing the results soon.
Thanks! We'll get it :)
Wow Franny fingers crossed its the coil and not something else more serious but wow why now etc so many questions can’t wait for the next instalment:)
I just watched first video and wrote this reply...
"With a stethoscope you can hear if the injector is clicking.
And how did you remove the sparkplug wire without getting zapped?
I have not quite finished the video. The spark did not appear strong"
Now I will watch part 2
Snap on coil tester,... generates a spark and one can tell if its strong enough by increasing the gap until it fails to jump. I'd post a pic but i lent it and was never returned. Worked great and very simple. Think it's basically a Ruhmkorff coil.
Side note, the guy wanted it to start his pulse jet, and worked for that.
First thing I would do is ditch those plugs and get the OE spec, likely NGK BPR6ES and gap them to spec. You also didn't show the porcelain of the plug, which could have a hairline crack and be your issue. Next is to get it together and let it idle! Do not rev it, no loads, restart it if it dies and let it sit and idle! It needs to relearn the parameters all over again. At the Porsche shop, we would have at least 1-2 of these come in during the Spring running poorly, and would just let it idle for 10-15min. and it would clear right up. If it doesn't clear up, unplug the air flow meter and see if that helps. With it unplugged, it basically reverts to a set base fuel map and will bypass a lot of inputs, but will also run better while having a vacuuum leak, so don't go replacing it right away if it smooths out. I also check the distributor cap to check that rotor and contact are good to go. You should've used the spark tester with the plug installed to make sure you were getting solid consistent spark through the sight glass instead of relying it to ground to 1 of the 4 prongs in the plug which was harder to see. Again, that ignition system was not designed to drive that type of plug and have seen them cause so much more harm than good, including induced feedback into the electrical system in one case study I have seen.
firstly, i enjoy your videos, and i have to say, you are a very good and thourough technician. i have a VERY similar issue with my 1985 euro bmw 635. i have brought it to 3 shops, who couldn't fix it. in fact one of those shops told me that there hasnt been one car in 35 years that they couldn't fix............well, i thought about the high idle, and abrupt power cutoff on deceleration. first thing i checked was the plugs because i had a feeling it was running lean, and sure enough they were white. apparently, none of the shops even checked that. so i looked over and over for vacuum leaks and found none. i found the aic to be bad, a kinked fuel line at the pump, and a messed up air flow meter. it now runs better, but still idles at around 1100 and the fuel virtually shuts off unless you are accelerating. i havent touched the injectors, but after watching your last video, i might replace all 6 and do the lines clips and etc. TY for your great video, but id go back and check for vacuum leaks and a faulty aic!
Thanks for that! I hope you get that magnificent 635 running perfectly :)
@@HeidiandFranny well i have to laugh as 3 shops apparently didnt even pull the plugs! pretty sad that there are so few "mechanics" anymore! they plug in a scanner and change parts! thats why i love your analysis of issues...........a true "technician"
I sure hope it is the coil... looking forward to the next video.
Really enjoying this series and I’m learning lots about the 3.2 👍
Me too actually :)
Hi Franny! I don't think you needed to send those injectors in at all. I just saw Ian Tyrrell in England try to tune a v12 Jaguar engine and found a few injectors not firing. He simply zapped them with 12 volts from a battery and kept doing that till they unstuck. He said to just zap them but don't leave them hooked up because then you will burn them out. He said they will stick if left to sit for a while. That seems to have been all that was wrong with yours since you left them sit for a year.
His UA-cam channel is Tyrrells Work Shop. He's like the pope of exotic cars. Lol
I thought sure you had a clogged fuel filter or line. I'm glad you tested the coil. That is pretty old.
I love watching Ian! The way he can tune a carb by ear is amazing :) I have seen that method to unstick them. RC said they would go back through them at no charge and they flow test them as well. They Are much smoother... At $300 a pop I didn't want to damage them.
Blast! I was sure the injectors would do it. Even though I want the engine to run as much as you do you are providing a very useful diagnosis tutorial! I have every confidence in you sorting this.
I had 2 Bosch coils fail intermittently like that back in the day, so I would not be surprised.
Fuel pump relay? Yes, carried one around for about 5 years until I needed it. When it dies there is nothing intermittent about it - game over.
Good advice!
Since you had alot of the car apart you might want to check the grounds on the ignition system and coil. A bad ground will give a phantom temp related issues. I chased one on a 530i BMW after I had the motor out, it ended up being a body ground that been painted and not cleaned well on assembly. Good luck on your hunt what ever it turns out to be.
Thanks for that. There are two main grounds - one between the car and the transmission and the other on the intake manifold. Both were cleaned thoroughly and re-installed. BUT, It would be a good thing to re-check them.
@@HeidiandFranny I've seen some coments on the airflow meter and it kinda jared my memory back to my Benz and BMW tech days, those were a royal pain. The potentometer in the airflow meter could develop dead spots or the vane itself could become sticky both could be temp dependant. The vane can sometimes be freed up with some light oil and the continuity of the potentiometer can be checked I beleive but, I'm sorry, I can't remember what connector pins to test at. Hope that is some help to you. I don't want to be the person who "knows" what your problem is just offering some suggestions.
Holy Cow Heidi, looking like the coil has failed. Great diagnostic.
Looking forward to finding out what the new problem is. When is the next installment coming out? Really enjoy your channel.
Hi Franny I noticed in the last video when you were using the spark plug tester that the spark was not fast/constant - it was slow/ intermittent. That tester should light up like an Xmas tree with solid spark.
Thanks John, I think that may have been more of a mismatch between the flashing and the camera shutter. But,... I'll check again to be sure.
Should be good to test flow of fuel pump. At idle it might give enough flow, but not under load. Looks like fuel pump or pressure regulator is acting up. To check DME relay, normally relays can be bypassed by using wire connected.
You may have a issue with the firing,but this is one incredibly tidy looking Carrera
Great video very well explained
Subscribed.
👍🏻
Thanks! Welcome :)
Great videos! Have you checked the alternator output and the cdi unit? I also like to check continuity of the critical wiring.
I enjoy watching yor videos. Back to basics is what I put alot of faith in. Hopefully the plug wires are correctly attached. Is the firing order correct? 1-6-2-4-3-5 from what I recall. When you had the seat lifted for the DME relsy I saw rusted studs and bolts. This is an environment for bad grounding. All grounds on the chassis need to be examined. Looks like your coil may be bad. If you were cranking the engine with spark wires disconnected and not grounded it is murder on the coil. Hopefully that’s what it is. My 2 cents worth.
I hope that it is as simple as a bd coil. I am always amazed at your clean gloves after working on this motor, like a brand new engine with gremlins.