This reminds me of the days when I was the responsible technician to calibrate the MFAC (main fuel actuator control) on a Solar International industrial natural gas turbine. The MFAC was an analog computer that worked to control the fuel to the turbine engine. In all control modes the output of the MFAC was a current signal (10 - 50 mA) to the Fuel Throttle. The MFAC did not have separate long and short trims, but rather combined the outputs of three different analog computations into one. The three analog computations were Proportional & Integral & Differential based on the controlling setpoint signal. It seems that you have been blessed with an ECU that apparently combined long and short term fuel trims together to get the needed “overall” fuel trim. Assuming that this vehicle had a MAP sensor, I kept waiting for you to pull up that P.I.D. for clues. As you well know, the MAP sensor ideally reflects intake manifold pressure and could be used to diagnose vacuum leaks real time using a scanner. Just thinking out loud. Hope this helps?
I called it that it was Scannerdanner you were calling. He's an amazingly nice guy! I always recommend his channel along with yours, you guys are awesome!!
@@SchrodingersBox good taste in subscriptions too, I subscribe to his and your paid sites. Best out there by far! I'm an extremely satisfied and grateful customer!
I know that on these Fords disconnecting the Neg cable won't clear the capacitors. Connecting a wire with alligator clips on each end from the disconnected Neg cable to the connected Pos cable for 5 minutes will clear the capacitors and reset the learned driving habit trends such as shift points, idle position for throttle body, everything. Made a huge difference for me Matt. After reconnecting the battery turn the key on and leave for 15 seconds, then start and idle the car in park for 10 minutes. Then go for a drive. Nice and easy. The CPU will relearn the valves that were previously stored. You probably know this but thought I'd mention it.
Matt, clearly the symptoms were consistent with a vacuum leak and it was diagnosed properly using the smoke test. The LTFT IS being adjusted by the ECU; simply isn’t being displayed properly. Note that with a vacuum leak, the ECU will still control the A/F ratio properly as long under steady state conditions provided the vehicle is operating in closed loop AND both (or all) control oxygen sensor(s) are working properly..the hesitation is caused by the ECU not being able to rely on the base map and the MAF sensor data (car will run too lean under acceleration). The oxygen sensor data are typically ignored by the ECU during hard acceleration or wide open throttle. Often, a vacuum leak will NOT trigger a fault code (check engine light), as the check engine light is diagnostics on the control circuits and sensors…which are still functioning properly with a vacuum leak. Check engine codes are a very useful tool, as is a scanner, but so is a smoke test, compression test, blowdown test…just a different way to get evidence to confirm a cause. Many mechanics now rely too much on scanners versus other readily available diagnostic tools (including multimeters, test lights, noid lights, etc.).
I had to rewatch through part 1 and 2 to determine that he did properly guess and fix the vacuum leak. And then was surprised that it was fixed. Tunnel vision on the LTFT. But did ignore the dash light problem. Which may well be related to the LTFT problem. Just me guessing now.
I did a 02 f150 a couple years ago and it wouldn't get out of it's own way it ran poorly and it took me a while to figure it out. It had all kinds of transmission codes that didn't make sense and o2 heater codes which somebody replaced them. It came down to a blown fuse in the power distribution box for the o2 sensors. Lesson learned check fuses first when you have codes that don't coincide with each other.
Years ago I had a misfire at low load low rpm on a Chevy LUV. Made me crazy for a day, turned out to be the center electrode insulator on plug one was cracked around its circumference up high. The plugs sit straight up in that engine allowing the insulator to slide down and block the spark causing a misfire, under higher cylinder pressure it didn't slide down and ran fine. That was over 35 years ago and I still have that plug.
I suspect if the engine was swapped the PCM may have also been swapped with it. That would explain the PIDs not mapping correctly - for example, it may be reading PID 32 & 33 when this PCM broadcasts that data on PID 35 & 36 (this is an arbitrary example).
To get the default injector on-time You could disconnect the oxygen sensors, the MAF- or MAP sensor, and the ECU would go in limp-mode. The ECU would then have to look up the values for the injector on-time in the factory default fuel map. Then You could record the injector pulse width at various engine speeds, then reconnect everything and record the difference in injector on-time. Then it would be possible to calculate the LTFT and see how much it compensates…
The phantom warning lights on the dash say to me that there's some sort of wiring fault such as a missing engine to body ground strap at rear of the engine or perhaps corrosion in the ECM connector(s).
This being an 02 I think it might still use ford “SCP” network. It appears like a can bus at first sight but it’s actually a transmit wire and a receive wire. I think the receive wire might have something to do with programming but I’m not too confident of my memory. This has been quite an interesting case study. Thanks for the videos!
Another weird thing I noticed was the digital odometer wasn't on until you put it into gear at 28:41. Definitely some weird electrical issues going on. I see some wire diagrams and a lab scope in the future if you follow up. Would definitely be a very interesting case study. Probably not DIY friendly though lol.
I was hoping you would chase the dash lights, it just seems weird that they came on, especially without any airbag code. Could it all lead to a bad ending resistor or sth weird like that?
"The EGR valve still needed to be fixed, but I don't think that'll be the issue with this car." Uh oh, sounds like "well it needed a new 'x' anyway!". Breaking your own rules? JK. Your honest with us and you were thoughtful enough to share this experience for us all to absorb something from. Still better than scotty kilmer, I appreciate your videos!
Hahaha I knew someone would bring that up lol. Yeah the only reason I changed the gasket on the EGR is because it was the only evidence for a vacuum leak and I was just hoping it would lower my fuel trims. the fact it raised them initially - that I can’t even begin to explain. That was a really significant vacuum leak and STFT responded after fixing it by increasing ???
@@NeiroAtOpelCC No, you would normally expect short terms to decrease after a vacuum leak is fixed. It would no longer need the extra fuel it was previously adding before the repair.
your point about dielectric grease is salient, it is an insulating grease... it prevents ingress of water and outgress of high voltage spark. the only time I recommend putting on an electrical connector is maybe on top of an earth to chassis bolt where there's evidence of prior corrosion just to prevent further corrosion... notice I said on top, not between... metal should be contacting metal.
Great video! It's OK now and then not knowing why things happen but yes, I'd be bothered by it too 😂. As other people have mentioned, I'd have as well a cheap OBDII adaptor because sometimes it's better than an expensive one. Imagine that for $10 you could have known it was a communication problem/wrong PIDs... 😄 And yes, you should give ForScan a go as well. Amazing piece of software, especially if you have the two-way adaptor for it (it costs maybe $15 or $20 in ebay) so you can send commands to the modules.
It's a interesting problem, I think that it could need a another kind of scaner or the PCM can have some internal problem that it don´t let clear the memory or show the LT. Another possibility cold be, that the name of the PIDS are wrong, I had a cause very similar with a Renault and the problem was a bad traduccion of the DTC A big hug Maat and well job.
I know it is probably too late for anyone to read this but, right at 25:00 about the dash lights being wrong, it made me think it might be a flooded car or there is an electrical problem possibly the computer.
As you said I would be very suspicious of previous mechanic involvement. Who knows what things they screwed with, the ghost dash lights are a very good indication I think that there is something electrically wrong thus affecting the reporting of the LTFTs
My guess is that some vehicles are mapped for a single total fuel trim in each bank and for this vehicle that total fuel trim defaults to short term fuel trim on scanners. Maybe there is a part number on the pcm that could be researched or a service manual for the vehicle.
No, it's not a single total because it showed short term trims around zero with the leak at the EGR. The long term is in there, those two tools just would not read it.
thanks for the comment sandbag (good to see you back) but Simon answered it correctly. the long term is there. there is no question. this is a communication issue, not a fuel trim issue.
From the video the only thing you change is the gasket, and cleaned a plug boot with to much dielectric grease. I'm thinking the plug boot might have been causing the stumble or the gasket fix . I don't see anything else you did. What cylinder did that over grease plug boot go to? Thanks great video .
I was thinking the same thing. Cleaning the dielectric grease off the spark plug terminals may have been the most significant thing that fixed the issue. Could we'll have just been multiple random misfires from the get go. Although not having LTFT's was a real head scratching rabbit hole🤣🤣👍
Having the same issue on a 2001 e350. 5.4 2v Small school bus No ltft and stumble and pops through the intake Did you ever figure out what cause the missing ltft
Do both your software based scan tools use a wireless dongle? I've had problems with the elm wireless connectors not behaving properly. I wonder if a wired cheapy scan tool would show any differently?
working on 2001 lincoln LS ... the P1000 code will not go away ... and my NGS scanner only shows 1 complete cycle (key on , run, key off) since last clearing ... in reality it is well over 100 or more ...
I have a 2001 Ford Expedition 4.6 XLT and I've been told from two different mechanics that they could not see the long term fuel trim levels on my vehicle. However, if I use my Bluetooth Bluedriver scan tool, I can see my LTFT. Very strange.
might be a partial-year change. i had a 96 ford ranger, but it actually wasn't completely OBD-II compliant and gave the codes of a 95 model (had to use the paperclip method, wouldn't work with a code reader). very few models were like mine, so it tripped people up.
Yep - just watched both parts of this 'fix' and I have three questions: Why isn't Vicky featured in more of your videos? What the hell is going on with your hair? And most importantly - why have I got a sudden and inexplicable craving for pumpkin bread? I'll probably come up with more relevant questions after I've digested the facts, but I had to deal with the important issues first. 👌
Haha! That hair! I tell him that he should look in the mirror before he starts filming .... he doesn't seem to care! 🤣 He always looked great in his early videos, I think he does this to drive me crazy.
@@legallass9905 Hi Vicky, I think it's good that he doesn't care; we certainly don't need Hollywood-style looks on this channel (which is just as well, because I think the term, 'great' is a bit of a stretch - lol). In truth, I'm probably just jealous because I can't grow enough hair to fit through a baseball cap. Great to see you taking part; you should do it more often. Now, where's my slice of pumpkin bread? 🍞😆
@@legallass9905 Great work in Matt's latest video! I really don't think he sees the problem - lol. At least he's taken your advice on board and made at least a small effort. 😃
Is it possible that this ecm uses a single bank long term and left and right short term? I have heard of this before but not sure on what type of vehicle. Along with that thought you may not be able to view the proper data PID for long term fuel trim because it is not bank specific?
(Edit: Sorry, didn't notice I was looking at a video from 2 weeks ago. ) Does the version of firmware loaded on that particular ECM needs to be updated in order to read the LTFT's? Lots of buggy firmware out there, and it's possible that rig never got an update. Another possibility is that whatever is causing those other lights on the dash to be lit may be interfering with the LTFT pid logic in the ecm. As you know, bad grounds/modules can manifest in very bizarre ways.
You did not check the software version on the engine computer. I think you may have a non-US tune. Not all markets require obd2 for example the UK only required it from 2004 (EOBD) and Australia from about 2006. Where it was not required at the time manufacturer took advantage of that and left things out. For example, my 97 BMW Z3 in the UK is not obd2 compliant. It does not have the concept of Long Term and Short term fuel trims. It gives the users "integrator" and "base" values instead so I suspect it's just an ax+b correction. The US 97 Z3 would be obd2 and would have a long-term and short-term trim and the chances are that it needs to be programmed to use the multiple cells instead of the simple ax+b.
The short answer: we don't need the values of LTFT on the scanner to know if it is positive or negative, we just need the injector time and compare it to the factory specs, and then do the calculation ourselves...
Does your scan tool display the open/closed loop PID and does it indicate closed? Seems kinda like open loop. Part 1 shows P1000 on your scan tool so the codes were cleared recently by someone. Unless you did that before you filmed the vid. Maybe there will be some codes after a couple drive cycles are completed. I would try disconnecting the tps or something to see if the PCM will even store a code. It might be senile.
I see what you are thinking but the thing is, the O2 works exactly as expected. - there is no way it can respond to variables like that unless it has solid electrical and good internal performance. the issue is with the fuel trim, not the O2.
Just returned a rental car that I've been driving for a few days. This was actually the first time I've driven a car with an electric parking brake - having managed to avoid them up until now. Alas, my fears were borne out: I hated it. I've always driven manual transmission vehicles, and I'm used to relying on a mechanical actuator to hold the car still on hills. As a fellow manual driver yourself, Matt, what do you think of these electronic alternatives?
Were you in generic mode.... don't forget OEM mode sometimes displays substituted values. Seems like in Pt 1 you did try generic. LTFT 11:06 -35 11:19 +35 Nevermind, should have watched the whole video before speaking.
Well one must assume that the computer can calculate, and adjust, LTFT since the STFT zeroes in when You introduce the vacuum leak or add propane. It just can't communicate it to the scanner. But the computer must know the value, and adjust the injector time, because SHTF and LTFT percentages are just values for how many percentages the injector time is changed. How do we then know how big the LTFT correction is? Well if You pull up the PID's for injector time, and compare them with factory specs or a known good, then we should be able to calculate the percentage of LTFT correction and see how it reacts to vacuum leak/propane and where it settles when the STFT is around zero percentage. There must be somewhere we can obtain the nominal value of the injector time for a known good engine, either from the factory manual, or someone with the same engine in good working condition....
@@SchrodingersBox thank You… and I have learned a lot of it from watching all Your videos through the years, and ScannerDanner and Pine Holloway Auto Diagnostics too… so keep it comming… there’s a lot out there that can benefit from You wisdom!
Those perfectly round numbers for the STFT don't look right to me, either. It makes me wonder if it's using a default fuel map for some reason. What a bugger. Great that it works better, but now it'll bug you until you work it out. :-)
I love the Australian accent even through text lol. yeah the round number fuel trim is a clue. it’s telling me the scantool isn’t communicating. this is a communication issue- not a lack of fuel trim.
I don't think a smoke machine is cheating for a DIY'er. My smoke machine is one of those large Christmas popcorn tins with a smaller bread tin ($1 from the dollar store) inside holding a lit charcoal briquette surrounded by baby oil. Two air couplers installed in the tin lid. One hooked up to air compressor on lowest setting, the other is the smoke hose. Hillbilly but it works -LOL! Found plenty of vacuum leaks in an old expedition which uses tons of vacuum hoses. Even the AC control unit is controlled by vacuum lines. Worse vehicle I've ever owned! Hate Fords.
@@joelopez40oz23 LOL, heck yeah! It's crazy how much smoke those walking chimneys produce. Forget Scotty Kilmer's cigar 'smoke machine' - just get your backwards capped neighbor boy in his skinny jeans to smoke test that baby!
why would you think a vacuum leak and how do you know that was the problem unless you have LTFT to validate? also what if it wasn’t a vacuum leak. where do you go since LTFT shows zero?
Hmmm I don’t see how that would happen. I could see if it was a pressure leak and you look for bubbles but I don’t see how on a vacuum leak it would help??
Hahaha it funny you say that because in an earlier video someone said I am a total hack because my garage is such a mess. Good grief, seriously??? I may not be a great mechanic but my garage is easily the cleanest and most organized on all yourube!
This reminds me of the days when I was the responsible technician to calibrate the MFAC (main fuel actuator control) on a Solar International industrial natural gas turbine. The MFAC was an analog computer that worked to control the fuel to the turbine engine. In all control modes the output of the MFAC was a current signal (10 - 50 mA) to the Fuel Throttle. The MFAC did not have separate long and short trims, but rather combined the outputs of three different analog computations into one. The three analog computations were Proportional & Integral & Differential based on the controlling setpoint signal. It seems that you have been blessed with an ECU that apparently combined long and short term fuel trims together to get the needed “overall” fuel trim.
Assuming that this vehicle had a MAP sensor, I kept waiting for you to pull up that P.I.D. for clues. As you well know, the MAP sensor ideally reflects intake manifold pressure and could be used to diagnose vacuum leaks real time using a scanner. Just thinking out loud. Hope this helps?
I called it that it was Scannerdanner you were calling. He's an amazingly nice guy! I always recommend his channel along with yours, you guys are awesome!!
Thanks!!! You have good taste in automotive repair channels!!
@@SchrodingersBox good taste in subscriptions too, I subscribe to his and your paid sites. Best out there by far! I'm an extremely satisfied and grateful customer!
I know that on these Fords disconnecting the Neg cable won't clear the capacitors. Connecting a wire with alligator clips on each end from the disconnected Neg cable to the connected Pos cable for 5 minutes will clear the capacitors and reset the learned driving habit trends such as shift points, idle position for throttle body, everything. Made a huge difference for me Matt. After reconnecting the battery turn the key on and leave for 15 seconds, then start and idle the car in park for 10 minutes. Then go for a drive. Nice and easy. The CPU will relearn the valves that were previously stored. You probably know this but thought I'd mention it.
Matt, clearly the symptoms were consistent with a vacuum leak and it was diagnosed properly using the smoke test. The LTFT IS being adjusted by the ECU; simply isn’t being displayed properly. Note that with a vacuum leak, the ECU will still control the A/F ratio properly as long under steady state conditions provided the vehicle is operating in closed loop AND both (or all) control oxygen sensor(s) are working properly..the hesitation is caused by the ECU not being able to rely on the base map and the MAF sensor data (car will run too lean under acceleration). The oxygen sensor data are typically ignored by the ECU during hard acceleration or wide open throttle. Often, a vacuum leak will NOT trigger a fault code (check engine light), as the check engine light is diagnostics on the control circuits and sensors…which are still functioning properly with a vacuum leak. Check engine codes are a very useful tool, as is a scanner, but so is a smoke test, compression test, blowdown test…just a different way to get evidence to confirm a cause. Many mechanics now rely too much on scanners versus other readily available diagnostic tools (including multimeters, test lights, noid lights, etc.).
I had to rewatch through part 1 and 2 to determine that he did properly guess and fix the vacuum leak. And then was surprised that it was fixed. Tunnel vision on the LTFT. But did ignore the dash light problem. Which may well be related to the LTFT problem. Just me guessing now.
I did a 02 f150 a couple years ago and it wouldn't get out of it's own way it ran poorly and it took me a while to figure it out. It had all kinds of transmission codes that didn't make sense and o2 heater codes which somebody replaced them. It came down to a blown fuse in the power distribution box for the o2 sensors. Lesson learned check fuses first when you have codes that don't coincide with each other.
I am proud to call you a mentor.
happy to be one!!
New info about dielectric grease. Ty. Never use but good to know how to use properly
Years ago I had a misfire at low load low rpm on a Chevy LUV. Made me crazy for a day, turned out to be the center electrode insulator on plug one was cracked around its circumference up high. The plugs sit straight up in that engine allowing the insulator to slide down and block the spark causing a misfire, under higher cylinder pressure it didn't slide down and ran fine. That was over 35 years ago and I still have that plug.
Treats and assistance...Vicky(Vickie) rocks!
yes she does!!! and easy on the eyes too!!
@@SchrodingersBox To quote "The Money Pit w/ Tom Hanks": She's good lookin' wool!
Thats really crazy and cool,I'm really looking forward to a update of some kind,thank u sir👍
I suspect if the engine was swapped the PCM may have also been swapped with it. That would explain the PIDs not mapping correctly - for example, it may be reading PID 32 & 33 when this PCM broadcasts that data on PID 35 & 36 (this is an arbitrary example).
I absolutely think you are correct man.
Good theory -- but that shouldn't hold true when using the scan tool as generic obd 2 mode.
Exactly what I was thinking. When he mentioned that there was evidence of a engine swap, that set off an "ah hah" moment for me
To get the default injector on-time You could disconnect the oxygen sensors, the MAF- or MAP sensor, and the ECU would go in limp-mode. The ECU would then have to look up the values for the injector on-time in the factory default fuel map. Then You could record the injector pulse width at various engine speeds, then reconnect everything and record the difference in injector on-time. Then it would be possible to calculate the LTFT and see how much it compensates…
The phantom warning lights on the dash say to me that there's some sort of wiring fault such as a missing engine to body ground strap at rear of the engine or perhaps corrosion in the ECM connector(s).
yes absolutely agree!! I would have liked to follow up on it but I needed to stay on target. but yeah I bet a shared ground explains that.
I agree. I’d be looking for bad grounds common to the indicated faults on the cluster.
I think pine hallow auto diagnostic had this problem
Bad ground passenger side kick panel
This being an 02 I think it might still use ford “SCP” network. It appears like a can bus at first sight but it’s actually a transmit wire and a receive wire. I think the receive wire might have something to do with programming but I’m not too confident of my memory. This has been quite an interesting case study. Thanks for the videos!
Wow part 2 already!
I don’t got time to waste lol!! get’r’done!!!!!
Wow..... never seen anything like this. Great video as usual Matt.
I enjoyed this, look forward to finding out what the problem is.
Another weird thing I noticed was the digital odometer wasn't on until you put it into gear at 28:41. Definitely some weird electrical issues going on. I see some wire diagrams and a lab scope in the future if you follow up. Would definitely be a very interesting case study. Probably not DIY friendly though lol.
great observation!!
I was hoping you would chase the dash lights, it just seems weird that they came on, especially without any airbag code. Could it all lead to a bad ending resistor or sth weird like that?
Me when I fix a car: Drives to strip club.
Schrodinger: Gets upset that fix worked then spends several more hours trying to figure out why.
LOL I should try your method- less stress but more expensive lol
Oh, your customer's wife will appreciate that!
Excellent diagnosis. Maetro. Mui bueno. Y eso. Es Excellent de su parte no kedarse con duda es mejor preguntar ante de kedar con duda
"The EGR valve still needed to be fixed, but I don't think that'll be the issue with this car." Uh oh, sounds like "well it needed a new 'x' anyway!". Breaking your own rules? JK. Your honest with us and you were thoughtful enough to share this experience for us all to absorb something from. Still better than scotty kilmer, I appreciate your videos!
Hahaha I knew someone would bring that up lol.
Yeah the only reason I changed the gasket on the EGR is because it was the only evidence for a vacuum leak and I was just hoping it would lower my fuel trims. the fact it raised them initially - that I can’t even begin to explain. That was a really significant vacuum leak and STFT responded after fixing it by increasing ???
@@NeiroAtOpelCC No, you would normally expect short terms to decrease after a vacuum leak is fixed. It would no longer need the extra fuel it was previously adding before the repair.
Whaaat? Part Two immediately following Part One? What’s this world coming to? 😂
Hahaha. leaving on business for a week so didn’t want to leave you hanging!!
your point about dielectric grease is salient, it is an insulating grease... it prevents ingress of water and outgress of high voltage spark. the only time I recommend putting on an electrical connector is maybe on top of an earth to chassis bolt where there's evidence of prior corrosion just to prevent further corrosion... notice I said on top, not between... metal should be contacting metal.
Great video! It's OK now and then not knowing why things happen but yes, I'd be bothered by it too 😂. As other people have mentioned, I'd have as well a cheap OBDII adaptor because sometimes it's better than an expensive one. Imagine that for $10 you could have known it was a communication problem/wrong PIDs... 😄 And yes, you should give ForScan a go as well. Amazing piece of software, especially if you have the two-way adaptor for it (it costs maybe $15 or $20 in ebay) so you can send commands to the modules.
Always fun your videos
Glad you like them!
Another awesome video!! Thank you your videos are excellent real world teaching moments. AAA+++
Looks like Matt has got some enjoyable thinking to do: you don't learn much from an easy fix!
It's a interesting problem, I think that it could need a another kind of scaner or the PCM can have some internal problem that it don´t let clear the memory or show the LT.
Another possibility cold be, that the name of the PIDS are wrong, I had a cause very similar with a Renault and the problem was a bad traduccion of the DTC
A big hug Maat and well job.
I know it is probably too late for anyone to read this but, right at 25:00 about the dash lights being wrong, it made me think it might be a flooded car or there is an electrical problem possibly the computer.
As you said I would be very suspicious of previous mechanic involvement. Who knows what things they screwed with, the ghost dash lights are a very good indication I think that there is something electrically wrong thus affecting the reporting of the LTFTs
On my snappy scanners the st trims and lt trims are in different sets of data pids
Could you use a break out box with your scope and see if you have any weird glitches in the network
Good thinking. maybe see network glitch when the LTFT flashes briefly or something.
At 36:30 the left LTFT went red 35 for a split second..
YES!!!! I believe that’s an indication there is a fuel trim there other than zero- and it’s lean.
My guess is that some vehicles are mapped for a single total fuel trim in each bank and for this vehicle that total fuel trim defaults to short term fuel trim on scanners. Maybe there is a part number on the pcm that could be researched or a service manual for the vehicle.
No, it's not a single total because it showed short term trims around zero with the leak at the EGR.
The long term is in there, those two tools just would not read it.
thanks for the comment sandbag (good to see you back) but Simon answered it correctly. the long term is there. there is no question. this is a communication issue, not a fuel trim issue.
From the video the only thing you change is the gasket, and cleaned a plug boot with to much dielectric grease. I'm thinking the plug boot might have been causing the stumble or the gasket fix . I don't see anything else you did. What cylinder did that over grease plug boot go to? Thanks great video .
yes this was on number 2- right under the EGR valve. yep good point that cleaning some grease off the spark plug is a variable I forgot about.
I know you know this but the invisible long-term keeps short term stoich
Dang Fords
yes that’s what i suspected. good way to describe it. LTFT was clearly working however it was just not showing.
I was thinking the same thing. Cleaning the dielectric grease off the spark plug terminals may have been the most significant thing that fixed the issue. Could we'll have just been multiple random misfires from the get go. Although not having LTFT's was a real head scratching rabbit hole🤣🤣👍
Having the same issue on a 2001 e350. 5.4 2v
Small school bus
No ltft and stumble and pops through the intake
Did you ever figure out what cause the missing ltft
Yikes!!!!!
I got home work.
Missed em both.
🤔🤔🤔🤔🤔
Do both your software based scan tools use a wireless dongle? I've had problems with the elm wireless connectors not behaving properly. I wonder if a wired cheapy scan tool would show any differently?
I have seen that as well.
Yes indeed I thought same which is why I tried auto tap because it’s direct wire. I also tried another direct wire one off camera too.
working on 2001 lincoln LS ... the P1000 code will not go away ... and my NGS scanner only shows 1 complete cycle (key on , run, key off) since last clearing ... in reality it is well over 100 or more ...
I have a 2001 Ford Expedition 4.6 XLT and I've been told from two different mechanics that they could not see the long term fuel trim levels on my vehicle. However, if I use my Bluetooth Bluedriver scan tool, I can see my LTFT. Very strange.
how bizarre!!!!
might be a partial-year change. i had a 96 ford ranger, but it actually wasn't completely OBD-II compliant and gave the codes of a 95 model (had to use the paperclip method, wouldn't work with a code reader). very few models were like mine, so it tripped people up.
I'm not familiar with AE but graphing PID helps to see changes
Yes I would never get a scantool without graphing.
Yep - just watched both parts of this 'fix' and I have three questions:
Why isn't Vicky featured in more of your videos?
What the hell is going on with your hair?
And most importantly - why have I got a sudden and inexplicable craving for pumpkin bread?
I'll probably come up with more relevant questions after I've digested the facts, but I had to deal with the important issues first. 👌
Haha! That hair! I tell him that he should look in the mirror before he starts filming .... he doesn't seem to care! 🤣
He always looked great in his early videos, I think he does this to drive me crazy.
I still look great!!
@@SchrodingersBox 😘😍
@@legallass9905 Hi Vicky, I think it's good that he doesn't care; we certainly don't need Hollywood-style looks on this channel (which is just as well, because I think the term, 'great' is a bit of a stretch - lol). In truth, I'm probably just jealous because I can't grow enough hair to fit through a baseball cap. Great to see you taking part; you should do it more often. Now, where's my slice of pumpkin bread? 🍞😆
@@legallass9905 Great work in Matt's latest video! I really don't think he sees the problem - lol. At least he's taken your advice on board and made at least a small effort. 😃
Is it possible that this ecm uses a single bank long term and left and right short term? I have heard of this before but not sure on what type of vehicle.
Along with that thought you may not be able to view the proper data PID for long term fuel trim because it is not bank specific?
(Edit: Sorry, didn't notice I was looking at a video from 2 weeks ago. )
Does the version of firmware loaded on that particular ECM needs to be updated in order to read the LTFT's? Lots of buggy firmware out there, and it's possible that rig never got an update.
Another possibility is that whatever is causing those other lights on the dash to be lit may be interfering with the LTFT pid logic in the ecm. As you know, bad grounds/modules can manifest in very bizarre ways.
You did not check the software version on the engine computer. I think you may have a non-US tune.
Not all markets require obd2 for example the UK only required it from 2004 (EOBD) and Australia from about 2006.
Where it was not required at the time manufacturer took advantage of that and left things out. For example, my 97 BMW Z3 in the UK is not obd2 compliant. It does not have the concept of Long Term and Short term fuel trims. It gives the users "integrator" and "base" values instead so I suspect it's just an ax+b correction. The US 97 Z3 would be obd2 and would have a long-term and short-term trim and the chances are that it needs to be programmed to use the multiple cells instead of the simple ax+b.
The short answer: we don't need the values of LTFT on the scanner to know if it is positive or negative, we just need the injector time and compare it to the factory specs, and then do the calculation ourselves...
GREAT IDEA!!!!
I would think it’s has a aftermarket program also would had look to see if any of the I/M have been disabled
Good point, I had a 2011 Malibu in my shop with this disable from the stealership.
would connecting scope to watch change in voltage would let u know if changing
voltage on what, sorry?
Does your scan tool display the open/closed loop PID and does it indicate closed? Seems kinda like open loop. Part 1 shows P1000 on your scan tool so the codes were cleared recently by someone. Unless you did that before you filmed the vid. Maybe there will be some codes after a couple drive cycles are completed. I would try disconnecting the tps or something to see if the PCM will even store a code. It might be senile.
yes actually in part one i confirmed fuel status as CL-1
i would think u should check power and ground to rear 02 and make sure
I see what you are thinking but the thing is, the O2 works exactly as expected. - there is no way it can respond to variables like that unless it has solid electrical and good internal performance.
the issue is with the fuel trim, not the O2.
All O2's work just fine.
That's a normal leak on the egr ot leaks past the valve rod
Tough one !
Just returned a rental car that I've been driving for a few days. This was actually the first time I've driven a car with an electric parking brake - having managed to avoid them up until now. Alas, my fears were borne out: I hated it. I've always driven manual transmission vehicles, and I'm used to relying on a mechanical actuator to hold the car still on hills. As a fellow manual driver yourself, Matt, what do you think of these electronic alternatives?
they're ghastly, can't stand'em
Is it possible that the o2 sensor wires are swapped?
no because that would not cause no fuel trim. it would just cause each bank to read opposite of each other.
Were you in generic mode.... don't forget OEM mode sometimes displays substituted values. Seems like in Pt 1 you did try generic. LTFT 11:06 -35 11:19 +35 Nevermind, should have watched the whole video before speaking.
it’s ok- I like seeing what people are thinking “in real time”.
you should of tried to look at global OBDII data and see if it showed any thing on the fuel trims
sorry i commented before finishing the video i saw you did that.
great minds thinking alike lol!!
What brand of smoke machine should I get???
i have a smoke pro I bought used from a mechanic.
@@SchrodingersBox Thanks Matt!!!
Well one must assume that the computer can calculate, and adjust, LTFT since the STFT zeroes in when You introduce the vacuum leak or add propane. It just can't communicate it to the scanner. But the computer must know the value, and adjust the injector time, because SHTF and LTFT percentages are just values for how many percentages the injector time is changed. How do we then know how big the LTFT correction is? Well if You pull up the PID's for injector time, and compare them with factory specs or a known good, then we should be able to calculate the percentage of LTFT correction and see how it reacts to vacuum leak/propane and where it settles when the STFT is around zero percentage. There must be somewhere we can obtain the nominal value of the injector time for a known good engine, either from the factory manual, or someone with the same engine in good working condition....
yep exactly. you definitely have scientific thinking process!!
@@SchrodingersBox thank You… and I have learned a lot of it from watching all Your videos through the years, and ScannerDanner and Pine Holloway Auto Diagnostics too… so keep it comming… there’s a lot out there that can benefit from You wisdom!
i believe there is an ecm problem in reporting the data
yep definitely some communication issue.
I believe it’s working- just not reporting the LTFT for some reason.
I have a 99 with almost the same issues, but my downstream O2 sensors stay at zero.
in that case you likely have a legitimate extreme lean condition. Richen it to see it O2’s respond to rule out bad sensors.
Those perfectly round numbers for the STFT don't look right to me, either. It makes me wonder if it's using a default fuel map for some reason. What a bugger. Great that it works better, but now it'll bug you until you work it out. :-)
I love the Australian accent even through text lol.
yeah the round number fuel trim is a clue. it’s telling me the scantool isn’t communicating. this is a communication issue- not a lack of fuel trim.
Autolite spark plugs are great for lawn mower engine but I would never use them in a vehicle engine
why not?
I wonder has anyone got a simulator that can connect to the ECU and test it?
I doubt it however you can easily test it by just looking at inputs and outputs at the pins.
Stuck egr?
No it isn’t stuck. EGR was leaking at the gasket but this is after where the EGR is closed. it’s essentially a vacuum leak.
@@SchrodingersBox But was it being operated by pcm but no fault code i guess
Probably you have bus communication problem cosed by short or ground which was obviously showed on dash board.
I don't think a smoke machine is cheating for a DIY'er. My smoke machine is one of those large Christmas popcorn tins with a smaller bread tin ($1 from the dollar store) inside holding a lit charcoal briquette surrounded by baby oil. Two air couplers installed in the tin lid. One hooked up to air compressor on lowest setting, the other is the smoke hose. Hillbilly but it works -LOL! Found plenty of vacuum leaks in an old expedition which uses tons of vacuum hoses. Even the AC control unit is controlled by vacuum lines. Worse vehicle I've ever owned! Hate Fords.
I dont consider using a smoke machine cheating. All a DIYer needs is a young person with a vaping apparatus to blow in a vacuum hose.
@@joelopez40oz23 LOL, heck yeah! It's crazy how much smoke those walking chimneys produce. Forget Scotty Kilmer's cigar 'smoke machine' - just get your backwards capped neighbor boy in his skinny jeans to smoke test that baby!
I think you really over thought this. Think a vacuum leak, run a smoke machine, boom, done.
why would you think a vacuum leak and how do you know that was the problem unless you have LTFT to validate?
also what if it wasn’t a vacuum leak. where do you go since LTFT shows zero?
Reasons to own a Ford
You could call it the art of fixing a car without fixing the car.
replace the long term sensors. Hehehe
I did - along with the blinker fluid!!
damn you gremlins!!
That there truck has brain damage. Solved
Vacuum leaks🤦♂️soapy water all day😎
why does water have to be soapy ?
@@SchrodingersBox it doesn't have to be but being soapy helps create and or show the signs of air easier👍just one method to use😏
Hmmm I don’t see how that would happen. I could see if it was a pressure leak and you look for bubbles but I don’t see how on a vacuum leak it would help??
@@SchrodingersBox totally right🤦♂️I had my diagnosis mixed up😁
Hahaha I was trying to be gentle about it lol.
Shop too clean... Throw some tools around and drizzle some oil and grease on surfaces...
Hahaha it funny you say that because in an earlier video someone said I am a total hack because my garage is such a mess. Good grief, seriously??? I may not be a great mechanic but my garage is easily the cleanest and most organized on all yourube!
I could help you with that... For a small fee. Can you tell I'm unemployed? Reduced to watching youlube videos...