Nice, sweet and simple , video flows along a a good pace. Paul I keep meaning to PM you but any time I am on the Forum I get distracted reading threads.
Excellent. Your channel has become my goto place lately. Always understand cars much better after watching your videos. Big thanks from irish tech here.
It's great to know how to use a scope, and sometimes, a scope is an invaluable piece of equipment! But, a lot of circuit diagnostics can be done with a test light and a DVOM. Circuit design knowledge is the best tool! Awesome stuff, Paul!
I fixed my buddy's 96 explorer with that same issue. It feels great talking about how I watch Scannerdanner and apply his techniques. Thank you . Merry Christmas Mr. Danner.
I have a 99 Mountaineer which is similar to the Explorer. When you mentioned the code FP Secondary Circuit Low I knew right away it was either the relay or a wire harness problem. I've studied the FP circuit on my truck, creating faults and taking voltage readings when I have time on my hands. My FP circuit should be similar to the Explorer in which my truck has a bias voltage of 6.8 volts that goes to a splice to the #5 load side contact, IFS and FP with the KOEO. The bias voltage is used for diagnostics and it will flag a code if the ECM doesn't see the right voltage. I know all this stuff because of you Paul so thanks again!
First, let me say that I love your videos. They are very informative and easy to follow. You have gained a fan here for sure. I wanted to make one quick clarification concerning the relay diagnosis. If I'm not mistaken, you mentioned the power lug or the side that is "hot all the time" in the relay box as being the "Load" lug. Actually that is considered the "Line" side that is hot all the time. The "Load" is whatever device is drawing power from it. This may be penny ante info but it can make a huge difference in repair work in A/C and D/C power systems. Anyway, keep up the good work and thanks for your time and energy to make these videos.
Great vehicle trouble shooting Info, I also have a much better understanding of electrical relays that can be found in so many other non automotive applications as well. Thank you for the extremely helpful knowledge!
I just had to do this same troubleshooting on a '95 Volvo 940 wagon, 206k miles. Long but interesting story ahead ... :) Complaint was, car would start and run great for the first time of the day ... but then a mile down the street at the first stop, it would shudder and stall, and become a no-start for the rest of the day. Let it sit overnight, rinse and repeat. The poor guy threw over a grand at the problem, but couldn't make it go away. He said he had recently replaced the fuel pump, so I focused on ignition (good example of why testing to verify is IMPORTANT!) - well, I had spark when it was running, and to my surprise, I had spark all the way until it stalled! I could've sworn it was ignition by the way each cylinder seemed to drop out one by one as the engine got hot - like a coil failure. Could clearly hear the fuel pump running, key on, so all the wiring, relay, fuse, computer, and pump was good. Hmmm ... Threw that exact same Actron pressure gauge you had in this vid on there, and saw zero psi! I yanked the pump, grabbed a yogurt container from the wifey and filled it with her nail polish remover (acetone), stuck the pump in there, got some long wires to keep sparks away, and touched the battery I had there in my driveway. Pump buzzed away, but ZERO flow! Not a single drop! I kept on playing with it, and I heard a POP, and had an acetone fountain with a noticeable sound pitch change in the pump. So, it was a bad check valve inside the pump! First time I've ever seen or heard of this type of failure, where it would just block itself up after the pump ran several minutes. Walbro pump too - those are normally pretty good units. I was relieved - guy had been chasing this problem for over a year, and the car has sat for the past year. Once that pump gets here, she should be a runner. :)
something to watch out for with fuel pressure gauges, which I learned the hard way, don't mix up the hoses from a different set, the fittings are not always the same and they don't press the Schrader valve in the gauge, so therefore the gauge stays at zero when you crank. the fittings for Mac gauge hoses are a little bit longer than for the Snap On gauge hose. First time it happened I warrantied the Mac gauge, second time I ended up buying a new Snap On gauge and it worked, but when I was swapping over some fittings, is when I discovered the difference.
Hey bud, you’re an absolute genius. Crazy smart at diagnosing. Love your vids. If there’s any way you can help me. Car won’t start, then it will, then I’ll turn it off, then it won’t start, then it will, then it won’t for about 15 times, then it will start consecutively for about 15 times. Over and over back and forth intermittently starting. Tried diagnosing it, unfortunately I’m not too advanced at diagnosing. Alternator is new. Just changed all spark plugs and wires. Ignition coil is good. Battery is new. The engine wire harness that plugged into the ignition coil was bare so I rewired it, put a new connector and wires. Spliced a few of the wires and used a heat shrink butt connector to connect the wires. Then I heat shrinked each wire individually then wrapped them all together in electrical tape together. Changed the camshaft position sensor while I repaired the wires. Don’t know what else it could be. PCV valve is new, don’t see any leaks. The problem first started when I would stop at red lights, it would stall on me. I’d have to start it back up then it would drive and stall again. Did it for a few days until one day it wouldn’t start back up and I was blocking traffic. Got it into a parking lot, opened the hood, took out the fuel pump fuse, put it back in, and it started up. Don’t think that was the problem but I took note of that, that it could be. Just today I went and bought a fuel pressure kit. Connected the fuel pressure gauge to the fuel rail, turned the car onto accessory mode to get the pump to turn on. 0 pressure on the line. Had a friend try to start it, showed no pressure while cranking. After a couple of tries trying to start it, it eventually started and the pressure went up to 39 psi. Now I’m stuck. If you can help I would appreciate it.
So you've confirmed when it does not start, that you have no fuel pressure right? Then the next step is to confirm that you have a good power and ground directly at the fuel pump connection, at the fuel tank, DURING the no pressure problem (so while you are cranking it). If it is good, you need a fuel pump. If it is not, you have a wiring problem. This is a very critical next step. I can help further AFTER this test is done
ScannerDanner I hooked the gauge up to it again today. Ran a lot of tests on it. Yesterday it was showing no pressure on the line at accessory mode. Cranked it and it wasn’t starting yesterday and still showed 0 pressure while cranking it. Got it to start yesterday and it went up from 0 to 39 psi every time it started. Got out there today and it showed 2-4 psi on the line while it was only in accessory mode. Cranked it and this time it started right up, (couldn’t get it to not start to check pressure while cranking again). Pressure went up to 39 psi again. Few minutes later after letting it depressurize itself, I hooked the gauge up to it. Did a on off on off on off accessory mode test on it about 10 times and it showed 26 psi at the end of the test. Cranked it and it started, this time the pressure stayed at 20 psi and dropped down to 18 psi while idling.
@@dylanpaulk7878 as I stated prior, you need to have a voltmeter reading of the fuel pump power and ground when it is NOT starting, when you have 0 or low psi. Everything else is speculation and you know me, I'm not about that. This is our next step. If you have 0 volts at the pump we turn right, if you have 12v at the pump we turn left...
ScannerDanner My dad put the voltmeter on the pump with a paperclip and the car hadn’t been started in a couple days so I don’t if that had anything to do with the battery, but we were skeptical of how to test it properly or which wire was the right wire but we checked both and 1 of them didn’t show anything and the other one showed 10 volts and we didn’t know how to check for ground. I’m sorry we are both learning. With that being said, we installed a new delphi fuel pump. Hooked everything back up, and gave it a fuel pressure test. Still 0 at the rail when put into accessory mode. Pressed in the shrader valve and nothing came out. Primed it and tried to start it, nothing on gauge and no start. Kept going at it and it finally started and pressure was only at 20 psi or 18 psi. Still no difference. Took the hose off the regulator and the gauge didn’t move at all. Went ahead and put in a new fuel pressure regulator. Pressed in the shrader valve and I guess we had to bleed the air out of the line. Fuel sprayed out like never before. Hooked up the pressure gauge, primed it into accessory mode. Took 3 times priming it for it to get to manufacturers psi. Bled the gauge and it went up to 39 psi again. Good to go! So I cranked it and it started right up and it stayed at 39 psi the whole time which was good. Took it on a test drive right after, pulled up to a gas station. Shut it off and came back out. It wouldn’t start. Same issue. Cranked it and cranked it and no start. After 10-15 minutes, it eventually started. Got it home and wondering where to turn now in the diagnosing process or if I should go back and test the wires again ..
@@dylanpaulk7878 Did you get this fixed? I'm so sorry for the late reply. Here is a link for a wiring diagram for your car. You MUST check these wires DURING the no pressure issue. Don't worry about the intermittent nature of this, you just need to do these tests when it is NOT starting eautorepair.adtrk.biz/?a=10817&c=24&p=r&s1=
Great info on the engine light going out while cranking telling you there's crank and camshaft signals. I'm here because I have zero fuel rail pressure on a 2000 Ford Windstar. The ECM is sending the signals just like yours did Scanner and I have swapped a relay as well as tested the old one which was not that old. Still zero pressure. Guess I need to be looking at the fuel pump or wiring going to it to make sure its getting power and ground. The inertia switch in the right rear jack panel is pushed in but not tested. That fuel pump is 20 years old so I'm betting it needs a fuel pump. Ah the good old days of changing a fuel pump on the road and ripping out in a few minutes.
@@ScannerDanner I was thinking if ground shows up at the relay on the pump wire that you have good ground, it could be shorted though so not 100% accurate. I didn't know which wire was for pump gr at the tank but 12v pos was easy to find with my power probe for prime and cranking. The new pump fixed it.😀 Sure ain't as easy as the old pumps on the motor you could change on the road side. That was my first tank drop job.
citroen c4 year 2012. 1.6 diesel. was driving then cut out. modules saying no comms with engine ecu.. autel live data showing 0 mbar fuel pressure even when cranking and with foot to floor engine starts badly. clicking sound coming from right side of engine too. what would you do next..?
I've got the same problem at the moment but not sure which is the rely, the ones I thought it was with 404 on the top I've changed them for brand new and it's still not starting... car is a 2010 facelift seat leon mk2 2.0 tdi cr fr 170bhp
With an inductive load like a motor, coil or AC clutch you get arcing across the relay contacts when the relay turns ON and when it turns OFF. When the motor turns off you also get the inductive kick back (high voltage spike) similar to what you see on the primary of an ignition coil. The arcing across the contacts is what kills the relay, the arcing leaves carbon deposits and pits the contact giving higher resistance (as you said Paul) which causes high temps and failure. For an inductive load the relay sizing is a bit different, in other words if the fuel pump draws 6A at full load you would not use a 6A DC rated relay. If you look at generic relays you will see a HP rating as well, this is to account for the arcing problem with an inductive load. There are 'snubbers' for the for the load side of the rely to keep them from arcing too. The only reasons these relays fail with burnt contacts is because it was a defective relay or the manufacturer cheaped out and used too small of a relay (or if they had used a snubber it would have been fine.) One other thing to watch out for is if the original relay has a snubber built in across the COIL. If it does you have to use a relay with the same type of snubber. The snubber across the coil prevents the inductive kickback from the coil from frying the driver transistor in the ECU.
I’m impressed n I’m a student that’s interested in your work n I need you help by giving me advice how to repair a clutch pedal coz it’s slippery when I start pressing it... can you please help me with you big fan of ur work
I ran into a 04 focus that had a malfunctioning pcm relay last week. I tested for battery voltage and resistance to ground on the control. it had had a high resistance on the ground and a bad relay. this caused a no crank situation do to no pcm ground on the starter relay.
Best video easily on UA-cam. Question, when you turn the car to the on position do you in the video hear the fuel pump prime with no pressure ? Because I can hear mine prime but still no pressure.
Not all systems will give a prime, but if you do hear one, that is a good indication that your pump is getting a power and ground. I'd still recommend checking them before making the call on a bad pump.
Good job man. Love it when a plan comes together 😄 it's amazing a few places I've worked in don't even have fuel pressure testers. Here in uk big expensive tools like that are bought by the garage owner normally
I connected my fuel pressure gauge to the fuel rail on the Schrader valve and have 0 fuel pressure. I thought I wasn’t connecting it all the way down . But not sure how much more tight it needs to be .
My system holds pressure throughout the day, but loses pressure over night. I've changed the the regulator and the fuel pump but still loses pressure over night. (no codes) I prime the system and it starts. Where do I go from here?
I have a problem with my 2008 2.0t FSI. One day I was driving and I had almost no power at all I could barely get up to speed. Then later i tried to start it and It cranks but won’t start, I have low fuel pressure I only have 4 psi. I replaced the in tank fuel pump, the high pressure fuel pump, fuel pump module, and the fuel filter. Do you know what else it could be.
Had a Camry with no pump power up sound but had a bad crank sensor could it be Toyota gives you one power up and no crank signal won't give another power. Up ? Threw me off
My 07 dakota randomly wouldn't start last friday and after doing a few tests i bought a fuel pump thinking mine was bad but after dropping my tank i found out mine was still working so i tried injector cleaner and my truck started n ran for the past 5 days but today my truck won't start. I don't have anywhere near as much pressure coming out of the release valve on the fuel rail so do you think my pump is failing or could it be a bad injector?
I have a 2003 merc mountaineer, it will run ,but there is no pump priming so it's takes a lot of cranking to start it. Is the prime pump separate from the main fuel pump? Any thoughts.
didn't check fuel pump circuit draw??? first always check it has gas. watched people screw around for hours on an empty tank. also seen it started with no pump relay in,seemed it had to crank a long time (reaching a certain rpm before it would start. did this have the pump driver module on the xmember by the spare tire that always rots out??? i get thr feeling this will be back
It started with the relay out only after I got the pump running again. It has 60 psi of pressure as I showed. A good system holds fuel psi on shut down. It was running off of residual pressure (I even said that in the video) What's the point of checking pump current draw on this? Burned pins and connectors is always a resistance problem right where it is burnt. It is never from excessive current in the circuit.
What if the engine starts after 3-4 keys then starts on first key throughout the day as normal? Then if left overnight, next morning again it starts at 3rd key?
I did a fuel pressure test on mine running rough sometimes..95 Cutlass 3.1...to high 80 psi..any help..the fuel pump is new put in about 3 months ago.. could the new pump just be bad..any help
You not only know your shit; you know how to communicate your shit. Extreme right of the bell-curve in both regards and have earned a subscribe from me. Look forward to more. Thanks.
someone sifened my gas out my car i put bout 1/2 tank but i can i reprime the pump i did it once when i replaced the pump do i need get more gas i took fuel line off the rail pump ocmes on but no fuel is coming up to the injectors if u cud respond asap plz n thnx
Just wondering but how does the computer know that the secondary circuit was low? Sensor wire on circuit somewhere that saw the engine was running and it lost power?
Without looking at the diagram, there is most likely a feedback circuit to the PCM that is tied into the pump feed. So if the computer is commanding the pump relay on, it expects to see system voltage on the pump circuit.
2004 Astro 4.3 no spark no fuel and fuel gauge died? Just stopped while idling? power at all plugs code B2961 key in ignition circuit malfunction U1255 class 2 malfunction,U1301 class 2 data link high? Can test pump 62psi? Is the BCM bad?
@@ScannerDanner yes was bad ground next to thermostat housing and bad coil. Your the best! My2006 BMW M5 Has been to dealer they say can't find anything? I think it's a ground needs boost in winter but Summer cranks and starts? In Winter no crank? You help me with this one I'll send you a gift from Canada.
Hi Paul given a load side pin had gotten hot enough to discolor the plastic in the relay/fuse box, would you suggest also checking the female spade terminal for pin fitment? I changed hundreds of headlight globes and burned up loom plugs in taxi cab headlights and found loose pin fitment in the female terminal a big culprit. Thanks for the videos.
Replaced my timing cover gasket and now car cranks but won’t start. Removed pump relay and fuse for long story reason. Triple checked i put them in right spot when done. How can i make sure i didn’t mess up timing? I can’t find my fuel rail
@@valkyrie_voodoo and if it ran before,but not now, then it is something you touched. Start by testing for spark and see if it is there. Also scan it for trouble codes.
ScannerDanner honestly i think i found it. Fuel pressure sensor. They are already notorious for going bad and i could have tripped it while unplugging relays.
Check your power and ground on the fuel pump to start with. Then you'll need some good service info. www.scannerdanner.com/forum/post-your-repair-questions-here/3757-need-service-info-check-here.html
My 93 town car runs. But,has no fuel pressure at the rail according to the fuel pressure gauge. Blows black smoke. I changed the fuel pressure regulator.
Great video. Thanks ! Have '08 expedition w/a schrader valve. hooked up a fuel pressure gauge and NO fuel pressure. Car runs fine... I suspect I have the wrong schrader valve adapter. Anyone have a part # for the right adapter?
So I know its says any car I bought a new fuel pump put it in no pressure at all replaced fuses and replace old fuel pump fuse but nothing and it's cranking good and everything it's a jeep liberty 03 I like the information you gave on the vid but do you have any thing on a jeep liberty 03 I've done a good amount of your steps but will keep trying love that jeep only 126000 miles on her and believe she has more live just need to figure this out
Great video ! Couldn't you check the coil pack while you were checking for spark as well to see if it was in good working condition before going to the relay, Mr Paul?
It is becoming more and more difficult to answer questions here. I have 80,000 people asking me for help now. So I have created a forum to help you guys better. It is free to join and we can exchange pictures, wiring diagrams and waveforms if needed to help guide you through the process of troubleshooting your vehicle. Thank you so much! Hope to see you there. Paul Danner (ScannerDanner) www.scannerdanner.com/forum/post-your-repair-questions-here.html
Quick question that has left me wondering for a couple weeks after first contemplating a second possibility in the start-up sequence: I just did an online search and found no related material. So I thought Danner might know. Since learning 2-3 years ago about engine priming that coincides with key-on, engine-off, it forever worries me about turning the key on like when using a scanner because of what could be repeated injections of fuel into the cylinders. But what if no injection takes place during this "primer" phase before actual firing of the cylinders? Instead, the real process would only get the pressure built without sending a signal to open the injectors and release fuel. That would make a lot more sense. Maybe everyone else knows this one already. For me, it is an area of understanding yet to settle. Do you know?
The prime period does not fire the injectors. It only prepares the fuel delivery system to achieve proper psi before you start cranking the engine (faster start up)
Really glad to learn that. Now I can stop worrying during the scan or whatever. Weird how it took me 2+ years to get this one right. I seem to recall asking one of my auto tech instructors and getting told that it does push fuel in there. It was only the other day when I started wondering if he was wrong or even if I may have heard him incorrectly. Anyway, thanks. Made my life easier knowing this for sure.
anytime! If you need additional help or have other questions: It is becoming more and more difficult to answer questions here. I have 80,000 people asking me for help now. So I have created a forum to help you guys better. It is free to join and we can exchange pictures, wiring diagrams and waveforms if needed to help guide you through the process of troubleshooting your vehicle. Thank you so much! Hope to see you there. Paul Danner (ScannerDanner) www.scannerdanner.com/forum/post-your-repair-questions-here.html
Good one. I will comply. That is way too many people asking questions. Much better like you have done to spread out the task among others, then fill in where useful. The ability to include attachments is an added bonus.
It is becoming more and more difficult to answer questions here. I have 80,000 people asking me for help now. So I have created a forum to help you guys better. It is free to join and we can exchange pictures, wiring diagrams and waveforms if needed to help guide you through the process of troubleshooting your vehicle. Thank you so much! Hope to see you there. Paul Danner (ScannerDanner) www.scannerdanner.com/forum/post-your-repair-questions-here.html
I wish mine was not easy. I've been dealing with my 04 Expedition for over 2 months now, everybody's charging me over $400 to put a fuel pump in it. I put a new one in myself, but I think the new pump is no good because I'm not getting any fuel pressure, but I'm not sure because I'm not a mechanic I'm just kind of one of those weekend warrior and I don't have $400 to pay on a fuel pump job 😭😭
@@ScannerDanner oh man thanks much for replying. I’ve done so much work: yesterday: 96 mustang gt driving me crazy, wont run. Put in 2 gallons fresh fuel no fuel pressure at rail-0 psi. new fuel pump from last year. Still i removed the fuel tank, pump and bench tested it, seems fine, good steady flow. changed fuel filter blew air from fuel tank to filter-no clogs blew air from filter to engine compartment -no clogs blew air from inlet hose by engine to fuel rail-no clogs getting power at harness by tank getting good spark charged battery no codes thrown ______________________ problem started last week , drove it out of garage to winterize and it died. Did a lot of work today (see list above). Put it back togther and it started and ran beautifully for maybe 3-5 minutes. then died and is doing EXACT same thing again…0 psi fuel pressure. Today: I checked the fuel pump fuse again, ok. Tested for power at the fuse and got 11.9 volts. Checked power back at the fuel pump harness and got 9ish, part of it I think was my ground because I got 10.5v once. I have a spare CCRM (this car doesn’t have a fuel pump relay in the engine compartment) the original one and I’m going to switch them, actually had taken off the tire and wheel liner when I saw your post.
@@28282222 those CCRM's were garbage but I can help you test it for sure. Step 1 is to get yourself a long jumper wire to connect to battery ground directly for your testing at the fuel pump itself. This will ensure that you have a good ground on your meter for all your tests. This will be critical moving forward. We need to test both the fuel pump power feed AND ground circuit while to pump circuit is energized. Check out what a bad fuel pump ground can look like ua-cam.com/video/rQ7tvIxQSt0/v-deo.html Then this one will help you too as far as the power and ground testing goes ua-cam.com/video/F2ZXhai-x9k/v-deo.html
I ran a jumper cable from the batter to near back of car, unsnapped the harness that fed to the pump and turned on the key to ignition. 4 pins. Top left was about 10.9v, top right about 6.5v. Both the bottom pins showed 0 volts. The battery showed about 11.4 v.
Also if you do get the paper version, put each page into a plastic sleeve and into a folder. That way you don't make a mess of the page with dirty hands! I
This is far best UA-cam videos I see out there most of all the videos just want to show you need to get a fuel pump
At 6:41 I swapped the relay with a known good. (Faulty relay). The rest of this video is how to test the circuit IF the relay was NOT bad
Nice, sweet and simple , video flows along a a good pace.
Paul I keep meaning to PM you but any time I am on the Forum I get distracted reading threads.
Excellent. Your channel has become my goto place lately. Always understand cars much better after watching your videos. Big thanks from irish tech here.
Thank you!
just got you a new sub for how great you explained everything thank you 6 years later
Thanks for the sub!
It's great to know how to use a scope, and sometimes, a scope is an invaluable piece of equipment! But, a lot of circuit diagnostics can be done with a test light and a DVOM. Circuit design knowledge is the best tool!
Awesome stuff, Paul!
Thanks brother
I fixed my buddy's 96 explorer with that same issue. It feels great talking about how I watch Scannerdanner and apply his techniques. Thank you . Merry Christmas Mr. Danner.
Merry Christmas to you too brother. Thank you
I have a 99 Mountaineer which is similar to the Explorer. When you mentioned the code FP Secondary Circuit Low I knew right away it was either the relay or a wire harness problem. I've studied the FP circuit on my truck, creating faults and taking voltage readings when I have time on my hands. My FP circuit should be similar to the Explorer in which my truck has a bias voltage of 6.8 volts that goes to a splice to the #5 load side contact, IFS and FP with the KOEO. The bias voltage is used for diagnostics and it will flag a code if the ECM doesn't see the right voltage. I know all this stuff because of you Paul so thanks again!
Thank you so much Charles!
Great video Mr. Paul you're the best teacher no one explain like u do man THANKS
Thanks so much!
I'm glad you pointed out that the pump prime operation is independent of the running pump control.I did not know that
Nice that you didn't have to get under the truck as usual. No rust in the eyes or fuel to the armpit.
but thats how you know if you have good flow :)
arielatom03 87 octane deodorant.
Man I'm glad that you exist.
First, let me say that I love your videos. They are very informative and easy to follow. You have gained a fan here for sure. I wanted to make one quick clarification concerning the relay diagnosis. If I'm not mistaken, you mentioned the power lug or the side that is "hot all the time" in the relay box as being the "Load" lug. Actually that is considered the "Line" side that is hot all the time. The "Load" is whatever device is drawing power from it. This may be penny ante info but it can make a huge difference in repair work in A/C and D/C power systems. Anyway, keep up the good work and thanks for your time and energy to make these videos.
We don't use the terms lug and line on the DC side of things in this field anyway. But thanks!
Great vehicle trouble shooting Info, I also have a much better understanding of electrical relays that can be found in so many other non automotive applications as well. Thank you for the extremely helpful knowledge!
I just had to do this same troubleshooting on a '95 Volvo 940 wagon, 206k miles. Long but interesting story ahead ... :)
Complaint was, car would start and run great for the first time of the day ... but then a mile down the street at the first stop, it would shudder and stall, and become a no-start for the rest of the day. Let it sit overnight, rinse and repeat. The poor guy threw over a grand at the problem, but couldn't make it go away. He said he had recently replaced the fuel pump, so I focused on ignition (good example of why testing to verify is IMPORTANT!) - well, I had spark when it was running, and to my surprise, I had spark all the way until it stalled! I could've sworn it was ignition by the way each cylinder seemed to drop out one by one as the engine got hot - like a coil failure. Could clearly hear the fuel pump running, key on, so all the wiring, relay, fuse, computer, and pump was good. Hmmm ... Threw that exact same Actron pressure gauge you had in this vid on there, and saw zero psi! I yanked the pump, grabbed a yogurt container from the wifey and filled it with her nail polish remover (acetone), stuck the pump in there, got some long wires to keep sparks away, and touched the battery I had there in my driveway. Pump buzzed away, but ZERO flow! Not a single drop! I kept on playing with it, and I heard a POP, and had an acetone fountain with a noticeable sound pitch change in the pump. So, it was a bad check valve inside the pump! First time I've ever seen or heard of this type of failure, where it would just block itself up after the pump ran several minutes. Walbro pump too - those are normally pretty good units.
I was relieved - guy had been chasing this problem for over a year, and the car has sat for the past year. Once that pump gets here, she should be a runner. :)
something to watch out for with fuel pressure gauges, which I learned the hard way, don't mix up the hoses from a different set, the fittings are not always the same and they don't press the Schrader valve in the gauge, so therefore the gauge stays at zero when you crank. the fittings for Mac gauge hoses are a little bit longer than for the Snap On gauge hose. First time it happened I warrantied the Mac gauge, second time I ended up buying a new Snap On gauge and it worked, but when I was swapping over some fittings, is when I discovered the difference.
I just bought the test light using the link you gave in the description! Happy Hanukah!
Nice! Happy Hanukkah to you too my brother
Hey bud, you’re an absolute genius. Crazy smart at diagnosing. Love your vids. If there’s any way you can help me. Car won’t start, then it will, then I’ll turn it off, then it won’t start, then it will, then it won’t for about 15 times, then it will start consecutively for about 15 times. Over and over back and forth intermittently starting. Tried diagnosing it, unfortunately I’m not too advanced at diagnosing. Alternator is new. Just changed all spark plugs and wires. Ignition coil is good. Battery is new. The engine wire harness that plugged into the ignition coil was bare so I rewired it, put a new connector and wires. Spliced a few of the wires and used a heat shrink butt connector to connect the wires. Then I heat shrinked each wire individually then wrapped them all together in electrical tape together. Changed the camshaft position sensor while I repaired the wires. Don’t know what else it could be. PCV valve is new, don’t see any leaks. The problem first started when I would stop at red lights, it would stall on me. I’d have to start it back up then it would drive and stall again. Did it for a few days until one day it wouldn’t start back up and I was blocking traffic. Got it into a parking lot, opened the hood, took out the fuel pump fuse, put it back in, and it started up. Don’t think that was the problem but I took note of that, that it could be. Just today I went and bought a fuel pressure kit. Connected the fuel pressure gauge to the fuel rail, turned the car onto accessory mode to get the pump to turn on. 0 pressure on the line. Had a friend try to start it, showed no pressure while cranking. After a couple of tries trying to start it, it eventually started and the pressure went up to 39 psi. Now I’m stuck. If you can help I would appreciate it.
So you've confirmed when it does not start, that you have no fuel pressure right? Then the next step is to confirm that you have a good power and ground directly at the fuel pump connection, at the fuel tank, DURING the no pressure problem (so while you are cranking it). If it is good, you need a fuel pump. If it is not, you have a wiring problem. This is a very critical next step. I can help further AFTER this test is done
ScannerDanner I hooked the gauge up to it again today. Ran a lot of tests on it. Yesterday it was showing no pressure on the line at accessory mode. Cranked it and it wasn’t starting yesterday and still showed 0 pressure while cranking it. Got it to start yesterday and it went up from 0 to 39 psi every time it started. Got out there today and it showed 2-4 psi on the line while it was only in accessory mode. Cranked it and this time it started right up, (couldn’t get it to not start to check pressure while cranking again). Pressure went up to 39 psi again. Few minutes later after letting it depressurize itself, I hooked the gauge up to it. Did a on off on off on off accessory mode test on it about 10 times and it showed 26 psi at the end of the test. Cranked it and it started, this time the pressure stayed at 20 psi and dropped down to 18 psi while idling.
@@dylanpaulk7878 as I stated prior, you need to have a voltmeter reading of the fuel pump power and ground when it is NOT starting, when you have 0 or low psi. Everything else is speculation and you know me, I'm not about that. This is our next step. If you have 0 volts at the pump we turn right, if you have 12v at the pump we turn left...
ScannerDanner My dad put the voltmeter on the pump with a paperclip and the car hadn’t been started in a couple days so I don’t if that had anything to do with the battery, but we were skeptical of how to test it properly or which wire was the right wire but we checked both and 1 of them didn’t show anything and the other one showed 10 volts and we didn’t know how to check for ground. I’m sorry we are both learning. With that being said, we installed a new delphi fuel pump. Hooked everything back up, and gave it a fuel pressure test. Still 0 at the rail when put into accessory mode. Pressed in the shrader valve and nothing came out. Primed it and tried to start it, nothing on gauge and no start. Kept going at it and it finally started and pressure was only at 20 psi or 18 psi. Still no difference. Took the hose off the regulator and the gauge didn’t move at all. Went ahead and put in a new fuel pressure regulator. Pressed in the shrader valve and I guess we had to bleed the air out of the line. Fuel sprayed out like never before. Hooked up the pressure gauge, primed it into accessory mode. Took 3 times priming it for it to get to manufacturers psi. Bled the gauge and it went up to 39 psi again. Good to go! So I cranked it and it started right up and it stayed at 39 psi the whole time which was good. Took it on a test drive right after, pulled up to a gas station. Shut it off and came back out. It wouldn’t start. Same issue. Cranked it and cranked it and no start. After 10-15 minutes, it eventually started. Got it home and wondering where to turn now in the diagnosing process or if I should go back and test the wires again ..
@@dylanpaulk7878 Did you get this fixed? I'm so sorry for the late reply. Here is a link for a wiring diagram for your car. You MUST check these wires DURING the no pressure issue. Don't worry about the intermittent nature of this, you just need to do these tests when it is NOT starting eautorepair.adtrk.biz/?a=10817&c=24&p=r&s1=
I really appreciate the detail and knowledge you share. Most helpful carguy I've come across on youtube.
I appreciate that! Thank you Berend van Rossum
Paul, I have found underneath the under hood fuse box, corrosion built up on terminals that have had the burnt relay scenario.
Great info on the engine light going out while cranking telling you there's crank and camshaft signals.
I'm here because I have zero fuel rail pressure on a 2000 Ford Windstar. The ECM is sending the signals just like yours did Scanner and I have swapped a relay as well as tested the old one which was not that old. Still zero pressure. Guess I need to be looking at the fuel pump or wiring going to it to make sure its getting power and ground.
The inertia switch in the right rear jack panel is pushed in but not tested.
That fuel pump is 20 years old so I'm betting it needs a fuel pump.
Ah the good old days of changing a fuel pump on the road and ripping out in a few minutes.
Yes sir, power and ground test at the pump is needed my friend
@@ScannerDanner I was thinking if ground shows up at the relay on the pump wire that you have good ground, it could be shorted though so not 100% accurate. I didn't know which wire was for pump gr at the tank but 12v pos was easy to find with my power probe for prime and cranking. The new pump fixed it.😀
Sure ain't as easy as the old pumps on the motor you could change on the road side. That was my first tank drop job.
Thanks scanner dan you explain thing to where people that work on their own car easy..
Excellent as always man, especially the relay circuit checks!
Star Wars could you put the
Merry Christmas Danner to you and your wonderful family
citroen c4 year 2012. 1.6 diesel. was driving then cut out. modules saying no comms with engine ecu.. autel live data showing 0 mbar fuel pressure even when cranking and with foot to floor engine starts badly. clicking sound coming from right side of engine too.
what would you do next..?
What about if I'm getting spark engine starts up fine but at the Schrader valve it does not show pressure ?
Focus on your fuel pump circuit for sure. But don't be in a rush to put a pump in it. Do some checks!
It showed for us less tools more intelligency, thanks Paul.
I've got the same problem at the moment but not sure which is the rely, the ones I thought it was with 404 on the top I've changed them for brand new and it's still not starting... car is a 2010 facelift seat leon mk2 2.0 tdi cr fr 170bhp
With an inductive load like a motor, coil or AC clutch you get arcing across the relay contacts when the relay turns ON and when it turns OFF. When the motor turns off you also get the inductive kick back (high voltage spike) similar to what you see on the primary of an ignition coil. The arcing across the contacts is what kills the relay, the arcing leaves carbon deposits and pits the contact giving higher resistance (as you said Paul) which causes high temps and failure.
For an inductive load the relay sizing is a bit different, in other words if the fuel pump draws 6A at full load you would not use a 6A DC rated relay. If you look at generic relays you will see a HP rating as well, this is to account for the arcing problem with an inductive load. There are 'snubbers' for the for the load side of the rely to keep them from arcing too.
The only reasons these relays fail with burnt contacts is because it was a defective relay or the manufacturer cheaped out and used too small of a relay (or if they had used a snubber it would have been fine.)
One other thing to watch out for is if the original relay has a snubber built in across the COIL. If it does you have to use a relay with the same type of snubber. The snubber across the coil prevents the inductive kickback from the coil from frying the driver transistor in the ECU.
Would that not be a loose female terminal not snuggly connecting to the male terminal on the relay?
Thanks Paul another great video , big thanks from the uk
I’m not getting any power or prime to fuel pump.
The float does read on gas gauge...
Any ideas?
I’m impressed n I’m a student that’s interested in your work n I need you help by giving me advice how to repair a clutch pedal coz it’s slippery when I start pressing it... can you please help me with you big fan of ur work
I'm here because Eric the Car Guy just said Scanner Danner's school (Rosedale Tech) is the one of the best!!
Thank you! And tell my buddy Eric I said thank you too!
I ran into a 04 focus that had a malfunctioning pcm relay last week. I tested for battery voltage and resistance to ground on the control. it had had a high resistance on the ground and a bad relay. this caused a no crank situation do to no pcm ground on the starter relay.
Best video easily on UA-cam. Question, when you turn the car to the on position do you in the video hear the fuel pump prime with no pressure ? Because I can hear mine prime but still no pressure.
Not all systems will give a prime, but if you do hear one, that is a good indication that your pump is getting a power and ground. I'd still recommend checking them before making the call on a bad pump.
@@ScannerDanner ok thank you for the tips I appreciate it.
Good job man. Love it when a plan comes together 😄 it's amazing a few places I've worked in don't even have fuel pressure testers. Here in uk big expensive tools like that are bought by the garage owner normally
thank you my friend
I connected my fuel pressure gauge to the fuel rail on the Schrader valve and have 0 fuel pressure. I thought I wasn’t connecting it all the way down . But not sure how much more tight it needs to be .
Power and ground checks at the pump would be next
Thanks a lot for such great information.
My system holds pressure throughout the day, but loses pressure over night. I've changed the the regulator and the fuel pump but still loses pressure over night. (no codes) I prime the system and it starts. Where do I go from here?
I have a problem with my 2008 2.0t FSI. One day I was driving and I had almost no power at all I could barely get up to speed. Then later i tried to start it and It cranks but won’t start, I have low fuel pressure I only have 4 psi. I replaced the in tank fuel pump, the high pressure fuel pump, fuel pump module, and the fuel filter. Do you know what else it could be.
Had a Camry with no pump power up sound but had a bad crank sensor could it be Toyota gives you one power up and no crank signal won't give another power. Up ? Threw me off
This video helped out alot. Keep up the good work.
Good content as always Paul
Thanks brother
dude, you are way too good!!! fun and educational
Great video ,,,what if pump is ok relay is ok but still no pressure ?
Check power and ground directly at the pump connector
Wicked I'll check this as soon as I get some daylight thanks!
I learned so much from your videos, thanks for do it
My 07 dakota randomly wouldn't start last friday and after doing a few tests i bought a fuel pump thinking mine was bad but after dropping my tank i found out mine was still working so i tried injector cleaner and my truck started n ran for the past 5 days but today my truck won't start. I don't have anywhere near as much pressure coming out of the release valve on the fuel rail so do you think my pump is failing or could it be a bad injector?
Great video Paul.
I have a 2003 merc mountaineer, it will run ,but there is no pump priming so it's takes a lot of cranking to start it. Is the prime pump separate from the main fuel pump? Any thoughts.
No the prime is within the programming. Same controls.
What is fuel psi DURING the long crank time you have?
didn't check fuel pump circuit draw??? first always check it has gas. watched people screw around for hours on an empty tank. also seen it started with no pump relay in,seemed it had to crank a long time (reaching a certain rpm before it would start. did this have the pump driver module on the xmember by the spare tire that always rots out??? i get thr feeling this will be back
It started with the relay out only after I got the pump running again. It has 60 psi of pressure as I showed.
A good system holds fuel psi on shut down. It was running off of residual pressure (I even said that in the video)
What's the point of checking pump current draw on this? Burned pins and connectors is always a resistance problem right where it is burnt. It is never from excessive current in the circuit.
Excellent Paul.
What if the engine starts after 3-4 keys then starts on first key throughout the day as normal? Then if left overnight, next morning again it starts at 3rd key?
I did a fuel pressure test on mine running rough sometimes..95 Cutlass 3.1...to high 80 psi..any help..the fuel pump is new put in about 3 months ago.. could the new pump just be bad..any help
You not only know your shit; you know how to communicate your shit. Extreme right of the bell-curve in both regards and have earned a subscribe from me. Look forward to more. Thanks.
Great teach, Paul
someone sifened my gas out my car i put bout 1/2 tank but i can i reprime the pump i did it once when i replaced the pump do i need get more gas i took fuel line off the rail pump ocmes on but no fuel is coming up to the injectors if u cud respond asap plz n thnx
Just wondering but how does the computer know that the secondary circuit was low? Sensor wire on circuit somewhere that saw the engine was running and it lost power?
Without looking at the diagram, there is most likely a feedback circuit to the PCM that is tied into the pump feed. So if the computer is commanding the pump relay on, it expects to see system voltage on the pump circuit.
2004 Astro 4.3 no spark no fuel and fuel gauge died? Just stopped while idling? power at all plugs code B2961 key in ignition circuit malfunction U1255 class 2 malfunction,U1301 class 2 data link high? Can test pump 62psi? Is the BCM bad?
we've been talking about this on another video right?
@@ScannerDanner yes was bad ground next to thermostat housing and bad coil. Your the best! My2006 BMW M5 Has been to dealer they say can't find anything? I think it's a ground needs boost in winter but Summer cranks and starts? In Winter no crank? You help me with this one I'll send you a gift from Canada.
@@glendekoker3682 let's move that one to my forum www.scannerdanner.com It is free to join and easier for me to do this stuff over there. Thanks!
So if u switch relays and do the cuircut test and theres no light then what does that mean? That there is a ground problem?
awesome, right to the point and very simple.....
Hi Paul given a load side pin had gotten hot enough to discolor the plastic in the relay/fuse box, would you suggest also checking the female spade terminal for pin fitment? I changed hundreds of headlight globes and burned up loom plugs in taxi cab headlights and found loose pin fitment in the female terminal a big culprit. Thanks for the videos.
Absolutely and I should have mentioned it but it wasn't the issue here. Good tip, thank you!
excelente diagnostic. testing. amigo.
Replaced my timing cover gasket and now car cranks but won’t start. Removed pump relay and fuse for long story reason. Triple checked i put them in right spot when done. How can i make sure i didn’t mess up timing? I can’t find my fuel rail
Did you have the timing belt off?
ScannerDanner nope not at all didn’t even touch it
@@valkyrie_voodoo and if it ran before,but not now, then it is something you touched. Start by testing for spark and see if it is there. Also scan it for trouble codes.
ScannerDanner honestly i think i found it. Fuel pressure sensor. They are already notorious for going bad and i could have tripped it while unplugging relays.
Thanks for this video brother. Thanks for everything.
On my 2003 Mercedes benz c240 I don’t have any fuel pressure, I have spark and I just put in a new fuel pump. What can be the problem?
Check your power and ground on the fuel pump to start with. Then you'll need some good service info.
www.scannerdanner.com/forum/post-your-repair-questions-here/3757-need-service-info-check-here.html
My 93 town car runs.
But,has no fuel pressure at the rail according to the fuel pressure gauge.
Blows black smoke.
I changed the fuel pressure regulator.
Great video. Thanks ! Have '08 expedition w/a schrader valve. hooked up a fuel pressure gauge and NO fuel pressure. Car runs fine... I suspect I have the wrong schrader valve adapter. Anyone have a part # for the right adapter?
Just get one that fits a Ford, they are all the same
I have a 2004 Cadillac Deville the fuel pump run no pressure coming And if you’re real what do I do please help
What would cause a lean WOT condition, long crank and a -10% fuel trim? No CEL and everything seems to test ok.
First thought with lean conditions and a -10% fuel trim is a MAF problem
ua-cam.com/video/QwGICKqWgM4/v-deo.html
Thanks for the reply. The car has a MAP sensor?
So I know its says any car I bought a new fuel pump put it in no pressure at all replaced fuses and replace old fuel pump fuse but nothing and it's cranking good and everything it's a jeep liberty 03 I like the information you gave on the vid but do you have any thing on a jeep liberty 03 I've done a good amount of your steps but will keep trying love that jeep only 126000 miles on her and believe she has more live just need to figure this out
My Guyyyy Keep It Going 💪
I guess I'm going to have to get your book for Christmas
Thank you! Merry Christmas
a scannie on Saturday , sweet
Yeah, I was late on my Friday video. My schedule has been crazy
loved it , it was an unexpected treat . diagnose on.
ScannerDanner Get work from Aleskyfinis
Thank you for what you do
I have a no crank with fuel pump prime but no start
will all 5 pin be layed out the same?
Great video ! Couldn't you check the coil pack while you were checking for spark as well to see if it was in good working condition before going to the relay, Mr Paul?
It is becoming more and more difficult to answer questions here. I have 80,000 people asking me for help now. So I have created a forum to help you guys better. It is free to join and we can exchange pictures, wiring diagrams and waveforms if needed to help guide you through the process of troubleshooting your vehicle. Thank you so much! Hope to see you there.
Paul Danner (ScannerDanner)
www.scannerdanner.com/forum/post-your-repair-questions-here.html
What basic scan tool would you recommend for occasional use?
great video way to go.thanks a lot
I had this happen but my issue was a 100% clogged fuel filter, 0 psi at the rail but would still run.
thanks for sharing. learn a lot
Quick question that has left me wondering for a couple weeks after first contemplating a second possibility in the start-up sequence: I just did an online search and found no related material. So I thought Danner might know. Since learning 2-3 years ago about engine priming that coincides with key-on, engine-off, it forever worries me about turning the key on like when using a scanner because of what could be repeated injections of fuel into the cylinders.
But what if no injection takes place during this "primer" phase before actual firing of the cylinders? Instead, the real process would only get the pressure built without sending a signal to open the injectors and release fuel. That would make a lot more sense. Maybe everyone else knows this one already. For me, it is an area of understanding yet to settle. Do you know?
The prime period does not fire the injectors. It only prepares the fuel delivery system to achieve proper psi before you start cranking the engine (faster start up)
Really glad to learn that. Now I can stop worrying during the scan or whatever. Weird how it took me 2+ years to get this one right. I seem to recall asking one of my auto tech instructors and getting told that it does push fuel in there. It was only the other day when I started wondering if he was wrong or even if I may have heard him incorrectly. Anyway, thanks. Made my life easier knowing this for sure.
anytime! If you need additional help or have other questions:
It is becoming more and more difficult to answer questions here. I have 80,000 people asking me for help now. So I have created a forum to help you guys better. It is free to join and we can exchange pictures, wiring diagrams and waveforms if needed to help guide you through the process of troubleshooting your vehicle. Thank you so much! Hope to see you there.
Paul Danner (ScannerDanner)
www.scannerdanner.com/forum/post-your-repair-questions-here.html
Good one. I will comply. That is way too many people asking questions. Much better like you have done to spread out the task among others, then fill in where useful. The ability to include attachments is an added bonus.
Hey Paul when you checked all power terminals to the relay. Is that a method you use on all fuel systems?
Pretty much all relays!
If the relay weren't cheap, and it was burnt, where would you look? Would that mean the fuel pump was drawing too much current?
It is becoming more and more difficult to answer questions here. I have 80,000 people asking me for help now. So I have created a forum to help you guys better. It is free to join and we can exchange pictures, wiring diagrams and waveforms if needed to help guide you through the process of troubleshooting your vehicle. Thank you so much! Hope to see you there.
Paul Danner (ScannerDanner)
www.scannerdanner.com/forum/post-your-repair-questions-here.html
ScannerDanner I like your videos.From Tampa, Florida. Thx for all your help. It's great. Keep up the good work.
Wicked subscribed thanks for the solid video
watch for them sticken inertia switches too.
paul what happened to james?
Play hunt the inertia switch --
They might have a problem before ... different type/color relay?
Great video thanks for the info!
Awesome. South Affica
I wish mine was not easy. I've been dealing with my 04 Expedition for over 2 months now, everybody's charging me over $400 to put a fuel pump in it. I put a new one in myself, but I think the new pump is no good because I'm not getting any fuel pressure, but I'm not sure because I'm not a mechanic I'm just kind of one of those weekend warrior and I don't have $400 to pay on a fuel pump job 😭😭
Great video.
But what are the causes if you don’t fond power in 2x pins on the fuel pump relay?
Double check I DURING cranking first. Tell me what you see. Also what are you working on? (Year, make, model and engine)
@@ScannerDanner oh man thanks much for replying. I’ve done so much work:
yesterday:
96 mustang gt driving me crazy, wont run.
Put in 2 gallons fresh fuel
no fuel pressure at rail-0 psi.
new fuel pump from last year. Still i removed the fuel tank, pump and bench tested it, seems fine, good steady flow.
changed fuel filter
blew air from fuel tank to filter-no clogs
blew air from filter to engine compartment -no clogs
blew air from inlet hose by engine to fuel rail-no clogs
getting power at harness by tank
getting good spark
charged battery
no codes thrown
______________________
problem started last week , drove it out of garage to winterize and it died. Did a lot of work today (see list above). Put it back togther and it started and ran beautifully for maybe 3-5 minutes.
then died and is doing EXACT same thing again…0 psi fuel pressure.
Today:
I checked the fuel pump fuse again, ok. Tested for power at the fuse and got 11.9 volts. Checked power back at the fuel pump harness and got 9ish, part of it I think was my ground because I got 10.5v once.
I have a spare CCRM (this car doesn’t have a fuel pump relay in the engine compartment) the original one and I’m going to switch them, actually had taken off the tire and wheel liner when I saw your post.
@@28282222 those CCRM's were garbage but I can help you test it for sure. Step 1 is to get yourself a long jumper wire to connect to battery ground directly for your testing at the fuel pump itself. This will ensure that you have a good ground on your meter for all your tests. This will be critical moving forward. We need to test both the fuel pump power feed AND ground circuit while to pump circuit is energized. Check out what a bad fuel pump ground can look like ua-cam.com/video/rQ7tvIxQSt0/v-deo.html
Then this one will help you too as far as the power and ground testing goes ua-cam.com/video/F2ZXhai-x9k/v-deo.html
@@ScannerDanner ok, will watch those videos and try. BTW put in the 96 CCRM and it had no effect whatsoever.
I ran a jumper cable from the batter to near back of car, unsnapped the harness that fed to the pump and turned on the key to ignition.
4 pins. Top left was about 10.9v, top right about 6.5v. Both the bottom pins showed 0 volts. The battery showed about 11.4 v.
Great information thanks.
how can I get one of your books
It's available on my website as an eBook or paper book
www.scannerdanner.com
Thank you!
Thanks
Recommend the paper book version as it's great to be able to thumb through a real book. Mine is on the arm of my chair right now!!
Also if you do get the paper version, put each page into a plastic sleeve and into a folder. That way you don't make a mess of the page with dirty hands! I
GreatTip!!
Well job 🧑🔧
What if it throws no codes ???
Great mechanic