Fuel Pump Relay Problem

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How to test a fuel pump relay.
Engine Performance Diagnostics chapter 16 pages 9-16
Symptoms
- fuel pump fuse keeps blowing
- intermittent no start
- intermittent low fuel pressure
- fuel pump relay buzzes
- when heater is turned on the fuel pump relay fuse blows
Fix
- repair loose main block ground
Tests shown
- fuel pump current measurement using a low amp probe and scope
- GM fuel pump relay diagram breakdown
- fuel pressure test
- fuel pump relay control circuit test
- fuel pump relay ground test
- fuel pump relay load side test
Tools used
- lab scope PicoScope 4425 4 Channel Standard Diagnostic Kit
www.aeswave.com/cart.php?m=affiliate_go&affiliateID=60df1b5cf6e5582af6ff81c728f42d0d&go=www.aeswave.com/PicoScope-4425-4-Channel-Standard-Diagnostic-Kit-p9276.html
- low amp probe www.aeswave.com/cart.php?m=affiliate_go&affiliateID=60df1b5cf6e5582af6ff81c728f42d0d&go=www.aeswave.com/Current-Probe-Low-range-Generic-brand-p8486.html
- wire piercing probe www.aeswave.com/cart.php?m=affiliate_go&affiliateID=60df1b5cf6e5582af6ff81c728f42d0d&go=www.aeswave.com/Adjustable-Insulation-Piercing-Test-Clip-with-B-plug-Inputs-p8507.html
- back-probing pins - AES' Electronics Accupuncture Probes www.aeswave.com/cart.php?m=affiliate_go&affiliateID=60df1b5cf6e5582af6ff81c728f42d0d&go=www.aeswave.com/AES-Electronics-Accupuncture-Probes-p9474.html
Playlist
- (Chapters 14, 15,16) Fuel Delivery and Fuel Pressure Testing
ru-vid.com/group/PLAFYVCyenqcrstVqfSc1PCbQ1pebuNIO6
Related videos
- Low Fuel Pressure from a bad fuel pump ground (Ford Ranger)
ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-rQ7tvIxQSt0.html
- Poor running, flashing CEL, no codes (bad computer ground) Toyota ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-44dP6X3QS5A.html
- Fuel pump electrical circuit diagnosis (no fuel pressure testing) GM ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-ZgNY3ZpjSsU.html
- How to test an electric fuel pump (no fuel psi testing) Ford
ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-F2ZXhai-x9k.html
- How to identify a bad main relay on a Honda (PGM-FI)
ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-6CMZ4g8n0FQ.html
For more information on this topic, I have written a “field manual” called Engine Performance Diagnostics which is available at www.scannerdanner.com as an eBook or paper book.
Want even more diagnostic training? Whether you are a DIY trying to fix your own car, someone looking to become an auto technician, or a current auto technician that wants to get more into diagnostics, subscribe to ScannerDanner Premium www.scannerdanner.com/join-scannerdanner-premium.html There is a 14 day free trial.
On ScannerDanner Premium I will bring you right into my classroom at Rosedale Technical College. You will find page for page lectures taken right from my book as well as exclusive classroom type case studies. What is so special about these classroom case studies? I pull live problem vehicles directly into my classroom and we troubleshoot them in real time, using and applying the theory and testing procedures we learn during the classroom lectures. There is no better on-line training of how to troubleshoot automotive electrical and electronics systems anywhere!
Disclaimer:
Due to factors beyond the control of ScannerDanner LLC, it cannot guarantee against unauthorized modifications of this information, or improper use of this information. ScannerDanner LLC assumes no liability for property damage or injury incurred as a result of any of the information contained in this video. ScannerDanner LLC recommends safe practices when working with power tools, automotive lifts, lifting tools, jack stands, electrical equipment, blunt instruments, chemicals, lubricants, or any other tools or equipment seen or implied in this video. Due to factors beyond the control of ScannerDanner LLC, no information contained in this video shall create any express or implied warranty or guarantee of any particular result. Any injury, damage or loss that may result from improper use of these tools, equipment, or the information contained in this video is the sole responsibility of the user and not ScannerDanner LLC.

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13 дек 2011

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Комментарии : 294

@GridIndustries 4 года назад

Excellent troubleshooting! I'm not good at wiring, but when you said the heater and the fuel pump both related issues on separate circuits, i immediately thought of a grounding issue - that seems to usually be what causes weird gremlins like this. I had a weird grounding issue on my car where the headlights would randomly turn off and I'd lose dash lights. It turned out I didn't have one of the main grounds secured. Thanks again!

@gizmo1-boss959 Год назад

Very nice lesson as always. This also would indicate that the oil pressure switch/circuit is no good, as once the engine is running the relay can be taken out of the loop and it should still continue to run. I realize that I am commenting on an old video, but for anyone that comes across it should also be aware of the oil pressure switch, which you did address on operation in the beginning when looking on the diagram.

@frank289frank 8 лет назад

Great video. Your knowledge of electrical systems and how to diagnose them is awesome . You give easy to understand examples of how to diagnose and repair what seem to be difficult problems. I was a mechanic for ford for twenty years before falling at work and hurting my back. I miss it terribly. Your videos bring me back to a time when fixing automobiles was not only easy for me but fun also. Your enthusiasm is refreshing. Thank you for your videos they inspire me to want to rectify my ASE tests. Especially the L-1. And electrical. Those were my favorite vehicle problems to repair.

@ScannerDanner 8 лет назад

+Frank Senick that's awesome Frank! It's never too late to get back into it. Especially if you focus on electrical systems. It is a lot easier on your back :)

@patbyrne5337 5 лет назад

Want to information about it where the relays are in the Micra 1041 litre want to know where the relays are in the micro one day 04 too old for Micra 1 litre want to know where to realise that relays are in relays

@patbyrne5337 5 лет назад

2oo4 micra 1 liter were are relays

@eFaZeHD 7 лет назад

Brilliant video, very good example of how to use a scope and diagnose either a bad ground or supply feed. Brill!

@perfritz2032 6 лет назад

Thanks! I've been watching several videos from you and I must say that not only your knowledge is great but also your teaching is superb!!! I'll keep coming back every time I have an issue with my Chevrolet Trans Sport, (Venture, Montana). 👍

@workonitm8 9 лет назад

Fella, I gotta say you know your stuff. I don't think very many people would have figured that one out. Thanks.

@troopbd 8 лет назад

+Norman Bates actually it takes him longer to find faults than it should since he is teaching while diag'ing, but any good diag tech would have figured that out, it is not as hard as it looks, honestly. you just need to know theory and system set-up

@RAFICKDAMISONMOYO 6 месяцев назад

Hey Paul Danner, Well Explanation for this Fuel Pump Circuit is very clear and making me to feel simple when the Faults Related to the Fuel Pressure issues come to me and im agree with your Motto " Don't Be A Part Changer" Thanks Forever Danner ❤❤❤❤❤

@amberwilder1463 8 лет назад

thank you so much for this! we just replaced the fuel pump and were still having this problem. so I searched and found this video and fixed it! awesome job, I'll be coming back to you for any other problems we have!

@teopatino 11 лет назад

This is the best educative video I've ever seen in this site,You are a real professional ,Thanks for helping.

@pico3423 12 лет назад

this is a perfect example of why i think your videos are the best--> well thought out real world troubleshooting!!!

@mypongo100 12 лет назад

Wonderful video. Learned a lot. My first reaction was to change the fuel pump, bad internal binding, etc. However, with proper testing and understanding theory of operation, I can see how my faulty reasoning would be an expensive lesson. Your methodical test procedure really made sense. Enjoyed following your explanation on the wiring diagram. Another thing, I learned was the importance of ground points. I didn't realize how critical they are and how they affect relays, etc. Thanks.

@ScannerDanner 12 лет назад

no, there are some frame mounted pumps but it is more common to be in the tank. some models offer an access cover in the trunk or rear seat area, which is nice.

@jeffreywatkins641 2 года назад

Your a very smart and knowledgable young man I really appreciate you putting this video out because I I have a similar problem with my nissan pathfinder.Thanks again I will like and share.GOD BLESS YOU.

@ScannerDanner 2 года назад

Thank you my friend, God bless you too!

@temotapia8597 11 лет назад

thanks mr. Paul for yuor videos, im in Mexico and i like all yuor videos you r a realy good teacher, now i understand my scanner and i will buy a scope. GOD bles you and your family

@texas77563 4 года назад

being able to see that relay open and close was pretty helpful. i want to order a set of clear relays to help with diagnoses

@Yosetime 4 года назад

That was totally cool!! Seeing the relay open and close and the diagnostic screen spikes was awesome! Thank you!

@Cuteness_love123 3 года назад

My El camino has a clear distributor it is awesome

@fivefortyeye540i 13 лет назад

Excellent excellent case study.. I was baffled in the beginning with the heater in the mix of things, that really through me a loop. Shared ground never cross my mind. Wiring digram interpretation is really key to figuring out what is going on within a circuit.

@cougar1972xr7 12 лет назад

so a question i seen the ground problem but as you shown in the wiring diagram the relay/oil pressure switch run in the same circuit so when the relay dropped out why did the fuel pump quit unless the oil pressure switch is not working or was the ground totally going in a open condition thanks hope you like questions i alway want to know

@jimmydean6981 10 лет назад

Great video , shows that you have to look in odd places sometimes. One normally wouldn't think there was a larger current load on a relays control ground. Great info as always Paul.

@OldSkoolF 3 года назад

Dan... Freakin Genius!!!!!! This helped save my 89 Regal from the crusher....

@ScannerDanner 3 года назад

Bad ground on the transmission?

@techgood 11 лет назад

Good Troubleshooter, Good Teacher - Thank you very much

@billrimmer5596 7 лет назад

Great interpretation of the scope readings. Gotta love Danner if he's on You Tube or any where else!!

@toyotatools9923 10 лет назад

A bazillion $ scanner, schools and training to find a Chevy ground fault.... priceless...! but... it was a stovebolt to begin with and would never ever own one newer than '60's..great video SD.... I loved it, your diagnostic skills are greatly admired here...73 and still wrenching...but not on those dogs...

@ScannerDannerPremium 10 лет назад

thanks my friend. I have much respect for my elders. I hope I live long like you to see my grand children. May God bless you and your family and continue to bless your hands and your mind as you continue in this field.

@toyotatools9923 10 лет назад

Hey SD thanks for that...You know of course I was not being disparaging in any way of your talent and training..love and appreciate your efforts you use to educate us old school dummies to the new tech..who would have guessed it in high school auto classes in the 50's working on Ford flat-heads and Chevy stovebolts it would have come to this ..?

@tedkay 12 лет назад

great explanation! it just shows when you know your job , you make it look easy! it appears you are a seasoned mechanic! great job! process of elimination only works when you know your trade!~ where can we find mechanics like you ? Oh! one more thing, it takes a little time to diagnose!~ you took less than 30 minutes...outstanding!!~

@Phantomas2011 4 года назад

Great case study!!! You’re the best too bad you’re not in the Los Angeles area, it would be a pleasure to let you diagnose my car problems but I’m learning a lot from you great guys! (Scanner, Eric o, Ivan)

@ricardobarron25 11 лет назад

I can't wait to get paid and buy your ebook. I've been watching your videos and they're great!

@jenhunter672 9 лет назад

@ScannerDanner TY!!! For years I always thought the oil pressure switch was for safety. Clearly it is in parallel with the circuit.

@ScannerDanner 9 лет назад

+Will Rogers you welcome! thank you

@consaka1 9 лет назад

+Will Rogers That is because sometimes it is for engine safety. This may be the exception or maybe safety is the exception. I'll leave it to scannerdanner to give the average percentages either way. I know it is a safety on older GM diesels of the 90's era. Least ways they won't run when that switch goes bad.

@ScannerDanner 11 лет назад

good question, with the bad block ground nothing was really working correctly. I have to look at the diagram again to give you a better answer than this.

@bmw540i 5 лет назад

Excellent piece of methodical diagnostic work 👍🏻👍🏻👍🏻

@Elchin206 6 месяцев назад

TCM ATA relay which is controlling with "-" from TCM. Black probe to pin on TCM and Red on relay "-" side. I got 1.5V (on ign.key on only). Is it the bad ground? I found how to check bad ground later on your channel. Thank you for all these videos🎉

@LynxStarAuto 11 лет назад

Super cool case study. Reminds me if your similar issue with the s6 Audi and how it had a loose nut on the firewall ground. Being a Euro specialist you have no idea how many times I see that.

@ScannerDanner 12 лет назад

I wish I had an easy answer for you. Unfortunately it is hard to find a good diagnostic tech in this field. Most mechanics are parts changers. A suggestion is go to iATN and search iATN's Auto Repair Shop Finder. This isn't going to guarantee that you find a good diagnostic tech, but I think it will increase your chances.

@ScannerDanner 12 лет назад

Thank you very much. Eric is a great friend. Nice you have you aboard!

@ScannerDanner 12 лет назад

@kenjackson1977 Do you have spark and injector pulse? Or does the engine run when you hot-wire the pump. All you said was the pump runs when you hot-wire it. I need to know to help you further.

@ckent2642 7 лет назад

would you be able to pull the relay, if the fuel pump still runs then that would narrow down to relay. Thought process on that was like you said the oil switch would take over and still allow voltage to the pump.

@bluegizmo1983 3 года назад

I know this video is old, but I'm confused about the relay... You said that oil pressure switch provides alternate power to the fuel pump once the engine is running and that you could pull the relay after it's running and it would stay running... So why does the relay switching off and on like that kill the engine? Obviously there is a problem there, but the oil pressure switch still should've kept it running... Edit: nevermind, I understand now. With that ground issue effecting the entire system (most likely), the oil pressure switch would also be loosing connection.

@danieljurgill1681 Год назад

You were right in your initial idea. The only way this engine fuel pump would stop and start because of a relay ground problem is if the oil pressure switch was not working. The oil pressure switch get power from a fusible link and it bypasses around the relay and connects to the same fuse and on to the fuel pump. The Oil pressure switch has no ground to worry about. The fuel pump itself has a totally different ground than the relay itself.

@zvonimirbobicex-4962 7 лет назад

but, shouldn` t that oil pressure switch take over when the relay fails???

@cap10moman 12 лет назад

Loved the video walk-through, as well as the process of elimination you used to get to the root of the problem! I'm not a mechanic by even a loose interpretation of the term (I like to do simple maintenance like change the oil, brakes/rotors, spark plugs, etc on my e39 540i). What would you recommend as a way to find a good mechanic to work on a car? One that will diagnose problems like you did in the video. Most I've been to would simply replace a pump/relay/etc and "see if that works".

@jorgenieto3151 8 лет назад

great teacher showing us how to think by deduction thanks a lot

@GRUSSNewton 12 лет назад

Every time I watch one of your videos I learn something! Keep up the brilliant work Paul!

@codywichman213 8 лет назад

That is one sweet capture. I was cool to see that the fp would operate with 4v on the ground. Very cool patern. One look at the ground voltage on the yellow trace, that was too cool

@ScannerDanner 8 лет назад

thanks brother

@nigelstringfellow5187 4 года назад

Fascinating Paul you should have been a forensic Detective this was so interesting

@ScannerDanner 12 лет назад

@ScannerDanner If the FP relay turns on and the injectors fire you need to replace the ignition module. I know, I know, "but I have spark" is what you are thinking. Listen, these modules will fail in that it will still control the coil, but not send the reference pulse (0-5v square wave) on the purple-white wire to the ECM. Without this signal the ECM will not see an RPM signal and will not fire the injectors and will not run the pump.

@maxwebster7572 8 лет назад

Great video. Nice to see what you can do with a scope. I have been doing this for years with a test light and a cotter pin. I may use a multimeter if I get really hard up. Granted this is an instructional video but why not use a cotter pin to ground out the control side of the relay and verify (a) relay works, (b) pump and load side work? All diagnostics in the video are great, I'm not trying to criticize here but a relay needs 2+ and 2- to work which is basic electrical....

@ScannerDanner 12 лет назад

@ScannerDanner Another clue to this problem is when you first turn the key on you should still get a fuel pump "prime". This is the ECM turning the FP relay on for a second to bring fuel pressure up. After this "prime" the ECM will NOT turn the FP relay back on until it receives an RPM signal (on the purple-white ref. wire). If you do not have a "prime" happening when you first tune key on, then we are barking up the wrong tree. I can still help you though.

@robertmccully2792 10 лет назад

i guess the best way to learn faster is to create faults on our own cars. The waveforms makes electricity visual instead of a invisible theory. I love it !!!!

@Snaponmike1 11 лет назад

Some nice multiplexed circuits over long spans. Pulse width modulated fuel control valves on CNG engines. Gas mass flow sensors. Coil on plug ignition with a separate module from the ecm

@koringn 12 лет назад

great stuff i see this nearly every day with the older cars were the earths play a huge part in things like this...

@Viper81766 13 лет назад

Brother, you keep out doing yourself. Amazing. God bless

@import0408 12 лет назад

This is my new favorite video. Awesome fix. Very nice

@roro560v8 13 лет назад

Thnx man that will help me at my auto tech school

@tedkay 12 лет назад

one last thnig! a good mechanic, listens to the customer~ it's called communication! it's like a doctor patient relationship~ So the customer was correct in his explaination of the cause of pump failure. didn't show on diagram sometimes it won't. great meachanics are the best trouble shooters!!

@ScannerDanner 12 лет назад

Thanks man! Hope you're enjoying it so far

@ScannerDanner 13 лет назад

@fivefortyeye540i Thank you, this one was a little tricky to film. There are so many different directions I could have taken this. Hopefully it was clear and not cluttered with too much info.

@danielseymore8719 8 лет назад

Further to my first question, the following is my real problem:I am driving the Ford Mondeo for 12 years now. Its a 2004 model 2liter petrol. It gave me excellent service. Then all of a sudden after 175 000 km, on the long road it started to loose power on uphill stretches and eventually comes to a stand still. Waiting for 10 minutes or so, start it again and then it will go for 10 km or so. It seems that as “something” gets hot it causes the problem. I at first thought it was the petrol pump but then someone told me, no, rather buy a new Fuel Pump Relay which I did and it then worked like a dream for 18 months. Then it started again with the same old story. Remember now the first relay worked for 12 years over 175 000 km, and the second one 18 months and only about 5000 km. I cannot tell you what really gets hot to have to cool down sothat when you start it it will go OK for a awhile. The Relay is supposed to work also the Air conditioner, ECC power (what ever that is) , High Beam lights, windscreen wipers, battery saver, fuel feed, the Horn, rear window wiper. After I established this I switched off all these “additional” uses (except the battery saver what ever that may be) and assumed it will then work the fuel pump only. No joy..... I have ordered a new relay but has not fitted it yet because driving in town on very short distances it gives no problems at all. Is there not perhaps a short causing not enough power to go the the fuel pump. But that does not explain why it stops working when I dont know what, gets hot. What is your opinion. I will greatly appreciate your views. Thanks

@martyisabeliever 11 лет назад

Paul,Guess I am asking the question from the perspective of being an owner/user of a Load Pro Dynamic Test Lead, and wondering if it would have revealed a bad ground from the terminal... perhaps I'll get a chance to test (or create a test environment to experiment and see if it will work)...

@franciscoreatas11 10 лет назад

Finally an actual auto electronic/electric master mechanic. Every one that I have dealt with only guessed.. By the way my 1991 Lexus was doing the same thing except it was blowing the fuse when I would turn on the radio. So I wrapped some copper wire on the fuse until whatever it was affecting it on the radio side burned up. The car works now, except no radio. I did this after multiple wanna-be's mechanics kept giving me bullshit diagnosis.

@ScannerDanner 12 лет назад

wow, thank you very much! what a great comment. keep watching, I have over 100 videos now and more to come.

@ScannerDanner 12 лет назад

This was a main block ground problem so it wouldn't matter where the power was coming from (relay or oil pressure switch), the problem would still be there.

@travisgelinas3078 9 лет назад

great video, it had to be a bad ground, if the positive trigger from the ecm was cutting out once running the oil pressure switch would have completed the circuit masking the problem.

@THERIGGEDONE 8 лет назад

Nice work Paul. I enjoy watching and Eric The Car guy, I've learned a lot from you guys. I also appreciate the use of the SO Verus, mine arrived yesterday, I can hardly wait to actually use it to fix things.

@ScannerDanner 8 лет назад

Thank you!

@mohawkmike142 11 лет назад

Excellent diagnostics Dan but seeing you pierce wires freaks me out. I live in the damp northeast and greenitis is a death sentence to a wiring harness. I know those tools are easier than rigging up backprobe taps and bridges but those little holes cause BIG problems. That said keep these great videos coming.

@Moeledon 9 лет назад

great video ..you get me nervus using the screwdriver as a pointer on the scopemeter .LOL

@ScannerDanner 12 лет назад

thank you very much and if you do you will not be disappointed.

@ScannerDanner 13 лет назад

@CoolasIce2 Im not sure, I'll look into it when I get a chance. I think any scope is better than no scope but then again there is some crap out there.

@ScannerDanner 13 лет назад

@CoolasIce2 I just checked out that scope. It is an old analog scope. It will do want you want but you will have problems with "glitch" captures because there is no play back. I would recommend you go on ebay and buy a used Vantage (not pro, unless you can afford it)). It is a graphing multimeter and will get you by for awhile. Plus the data base in the tool is unmatched in this field. I have had students pick them up for around $200

@nandor690 11 лет назад

Good video. Very amusing problem and very amusing colored diagram explanation

@mbs5328 7 лет назад

Is the oil pressure switch not working? Why didn't current keep flowing to the fuel pump through the alternate power feed (oil pressure switch) when the fuel pump relay was turning off? I think there must have been another problem here in addition to the bad ground on the control circuit of the fuel pump relay.

@ScannerDanner 7 лет назад

There are main computer grounds on that same stud. There was no other problems with this vehicle

@robertmccully2792 10 лет назад

good video,,, i bought your book, but i have to watch the videos to make sense of the lesson for us beginners. In your next book please show the test lead hookups locations not just in the videos.. I would rather have fewer lessons and more books showing lead hookups and wire diagrams... Because of your videos i realized i had to have a scope, so i bought a used Ultra Midis. It makes so much more sense seeing waveforms instead of a one dimensional DVM/O/A meter.

@ScannerDannerPremium 10 лет назад

Have you seen any of my premium channel videos yet?

@halleffect1 12 лет назад

another good vid. been meaning to get the ebook, finally did.

@wombat696969 11 лет назад

Must say, very good video, very informative.

@inkncraig 11 лет назад

Excellent, excellent, excellent video.

@jquin45 11 лет назад

That was awesome. Thanks for sharing the knowledge.

@martyisabeliever 11 лет назад

Dan excellent video wondering? Would a ground V-Drop test have been a valid test to prove the existence of a bad chassis/signal ground at the OBDII connector terminals 4 and 5??? and... where is your e-book link?

@ScannerDanner 13 лет назад

@spelunkerd Nice, I have never heard that quote. I like it too. The oil psi switch is simply there as a backup in case the relay fails. Of course the other side of that oil psi switch runs the oil psi gauge or light, so it serves two functions. I don't know why GM felt the need to backup the FP relay. No one else is doing that. Seems like a waste of copper wire to me. They must have had a lot of problems with this circuit early on?

@TheZemun 5 лет назад

@ScannerDanner By far this is the most detailed video with complete explanation of the issue . Kudos to you man! I have Opel Omega A 2.0i from'88 and the fuel pump relay get burning hot but doesn't blow the fuse . Weird. I also run my car on LPG and turn off the fuel pump but relay still getting hot. No one can find a problem .Still driving it that way . Checked for ground but can not find it . Any suggestions on this one I appreciate .

@ScannerDanner 5 лет назад

It is not abnormal for a fuel pump relay to get very hot or any relay for that matter.

@TheZemun 5 лет назад

I see ... But still , to be sure I always carry the spare fuel pump relay . Thanks.

@ScannerDanner 5 лет назад

@@TheZemun nothing wrong with that, just wanted you to know how surprised I was the first time I realized how hot these things actually get

@nickrtvt2 12 лет назад

probably going to buy this ebook once paul replies to a question i emailed. anyone have any other recommended youtube channels or ebooks that are worth watching or buying?

@abyssmal16 12 лет назад

You are awesome Paul. If i buy your e-book i'll have some kind of guide to learn how to diagnose problems like you did? I'm a begginer mechanic and current(and begginer) student of Electronic Engineering and i'm interested in learn this stuff. Thank you for your excellent videos!

@SuperClutchy 12 лет назад

great video just bought a 93 f150 runs like a dream.but after 30-40 min it starts stumbling and cutting off i change fuel fliter and pump and still do the same thing what u thing costing the problem.live in the bahamas

@larryashley4046 6 лет назад

SuperClutchy 1988 dodge 3.0

@tewildabryant8342 11 лет назад

You said in your video that the fuel pump oil pressure switch is not there to protect the engine but to serve as an alternate route in which the current could travel. My question is will the fuel pump oil pressure switch keep the vehicle from starting?

@juliorodriguez5963 11 лет назад

Very professional lecture. thanks.

@angeliquevanmaanen9753 12 лет назад

nice video good explanation ,i learnd a lot of your videos !!

@ScannerDanner 12 лет назад

@silkylove1000 if the car is running fine and your fuel psi is good i wouldn't worry about it. the rpm test has some gray areas if you ask me.

@Cuteness_love123 3 года назад

I enjoyed this knowledge fully can I fly you to Vegas to troubleshoot my 1995 Buick century wagon at this point I’m atleast 80% sure it’s a wiring issue

@Cuteness_love123 3 года назад

The fuel pump was my most recent replacement and I’m thinking maybe same wiring problem all along was never the pump

@Cuteness_love123 3 года назад

Shoot I swapped my cat just to be safe

@ScannerDanner 3 года назад

95? What engine? What is it doing? Do you have fuel pressure, injection pulse and spark?

@Cuteness_love123 3 года назад

I definitely have spark after watching this I am checking fuel pressure tomorrow it’s a 3100 odb1 and computer wont tell me anythingi have trouble with hard start once starts bogs and idles badly then if an drive a mile or so all seems well until next start usually

@spelunkerd 13 лет назад

@ScannerDanner That sounds a lot like a quote from Isaac Newton. It went like this, "If I have seen farther, it was by standing on the shoulders of giants...." I love that quote, and I love standing on shoulders, ha ha. Why is that backup circuit from the oil pressure switch there?

@mikewithers7685 10 лет назад

Love this video ! I have one question. Had a car in the other day and customer complained of long crank with his chev lumina. Did not get a fuel pump prime when key was turned on. noticed fuel pump wire dia was nearly the same as the car on this video.I noticed the red wire @ relay is the fuel prime. Where does that red wire get its power from ? didn't get much time to look at the car but gonna have to dive in Monday morning.thanks.

@ScannerDannerPremium 10 лет назад

Watch my video on "fuel pump electrical circuits " it will answer your questions about this system

@soroushchabavi4230 4 года назад

I wish you could do some transmission work. I would defiantly subscribe.

@pitchforkpeasant6219 Год назад

Im now curious given the video and my current issue if there was no oil pressure if the circuit/ecm would shut down the fuel pump. My fuel pump is having issues and ive seen when such happens the oil pressure gauge will read almost max pressure. Am wondering if the fuel pump and oil pressure were tied together purposely as a safety measure

@ScannerDanner Год назад

It will not, it's simply a bypass circuit. Maybe old, old designs when this was first developed. But that's not what this one does.

@MrJgonzalez2 12 лет назад

Paul,would the fuel pump feed wire show high amperage if it was intermittently touching ground?

@andrameda1 5 лет назад

Wow, this is exciting, quoting Don Rickles wife on there honey moon. What happens when there is no power on load side and no power on control side on fuel pump relay pins ? Is it a short to ground and power or is it a burnt computer?

@ScannerDanner 12 лет назад

good question and it should have, I guess the answer lies in the multiple grounds that share this location. it's been so long since I worked on this. sorry, I don't have a good answer for you.

@luisacevedo324 11 лет назад

Hey Dan have a question I have a 1999 GMC safari van Meyrou fuel pump relay gets extremely hot could it be that it's holding too much load because the oil pressure switch is bad thank you

@ScannerDanner 11 лет назад

Thanks man! If you get me some buyers, I will take care of you in the form of some free video lectures. Just have whoever it is mention your name in their communications with me. Thanks again

@Mikesky10 8 лет назад

why when the relay was turn off the oil swicht dindt do its job and keep the pump energize???, was the oil swicht bad or it was energizing but the pump keep turn it off because of the bad main ground?

@Filmaker25 12 лет назад

Don't fuel pumps make some noise to just show they are operating?

@rob0rat 11 лет назад

Would you be able to identify the bad ground by voltage drop from relay control ground to battery negative?

@ScannerDanner 13 лет назад

@TRcustomengineering No problem and than you for your comment. I have nothing and can offer nothing outside of Him.

@dreamer2355 13 лет назад

Excellent! Love these video's! Keep them coming!

@zvonimirbobicex-4962 8 лет назад

cool! ...a question: when koeo, why is the green line(power for the relay`s control side)behaving exactly the same way as the yellow line(relay`s control ground)...when you turn on the heater...and then when you wiggle that bad ground?...my guess: bcus they both are as one, since there is no power to the green line with the koeo

@ScannerDanner 8 лет назад

Because the power for the control is coming directly from the computer which is also being affected by a poor ground. Make sense?

@MrJgonzalez2 12 лет назад

Is it possible to determine a faulty pump based on speed, calculating from the humps? Or based on pattern only?