intermittent fuel pump power

[ezdaar]

rant deleted.

Advice added.

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Vehicle no start,
Check spark, got spark? yess.

Vehicle start, No.
Check fuel pump, Does it hum? no. change pump.

Vehicle start, No. Does fuel pump hum, yess.
Change fuel filter. <---- should be done regularly anyways.

vehicle start? no.
Check pressure before and after regulator, Got pressure both sides? No. Change regulator.
Pump hums but no pressure, change pump. look for blockage in fuel line.
Disconnect line at pump and regulator. shoot air through line.
No air? clogged line, replace line.

Vehicle start? no. Change spider injector.

Vehicle start, Yess.



You have spent over a week with a "mechanic" trying to fix a simple fuel issue..

Get a new mechanic.

 

[SunlitComet]

if doable try a injector balance test it will tell you if the injector are being fired by the pcm and if you watch for movement on a pressure gauge at the same time you can see if they are pushing out fuel and in a balanced way. that with a injector noid can help determine if the pcm is even outputting a driver signal for the injectors.

 

[Brendyn]

anybody else have any other opinions on what my problem could be or had the same issue, and like I said if anyone is very knowledgeable in obs trucks and is local to me rock island Illinois 61201, very close to davenport iowa also I would gladly pay you to help me fix my truck ive been without it for weeks and its my only transportation

Did you ever figure out this problem same thing happened to me. I have an 02 z71 it’s had a really hard life before I got it and at first it was all good the previous owner drove it from the panhandle of texas to the middle of Oklahoma with out a single problem I drove it for about 2-3 months and and in that time I drove it to border of Oklahoma and Kansas and pulled a my brothers equinox back but I had my buddy back it out of an alley way and bumped a light pole and the instrument cluster and and the rest of the dash flew back at him and ever since then the security light, fuel low light battery light and the check 4x4 light came on. After that it still drove the same just the instrument cluster goes on and off so I parked it for about 2-3 weeks. I ended up having to drive it to the store less then 2 miles away I get almost to the stop sign 1/8 mile down and it starts so to sputter and dies that that was the last time it turned over I changed the fuel pump no charge check the old one and it worked better then the new one tested the wires for energy and found out there’s nothing going to the pump I check all of the fuses and a lot lit up but the crank didn’t and I’ve changed it with a full pack of fuse for it and now of them got any juice at all so I checked a few more to do with emissions and what not and same that happened to them so I called the mechanic next to my job and he suggested to check the ecu next to the battery so I went out and bought a pre flashed ecu corresponding to my vin and put it in and nothing

 

[Brendyn]

if doable try a injector balance test it will tell you if the injector are being fired by the pcm and if you watch for movement on a pressure gauge at the same time you can see if they are pushing out fuel and in a balanced way. that with a injector noid can help determine if the pcm is even outputting a driver signal for the injectors.

Just wondering if your still replying on this page need some help and you seem like you know your way around 4x4 Tahoe’s

 

[Fless]

Just wondering if your still replying on this page need some help and you seem like you know your way around 4x4 Tahoe’s

First, go to the Introduction forum and introduce yourself. Then feel free to post comments, questions, etc. in a new thread in your year's forum for the issues you're experiencing. You'll get better responses if the thread is in the correct year's forums. Also, it doesn't hurt to put a little of your truck's info in your signature so we can see what you have each time you post.

 

[Eman85]

If you ran power to the pump and it didn't pump gas the pump is bad. If your mechanic got the pump to run and had 35PSI the pump is bad. It's not that complicated of a system to figure out.

 

[JackFox]

your mechanic sucks. he barely tested anything. He did 15 minutes worth of testing it sounds like. your truck was de-prioritized. get it to another mechanic. Your issue is easy for someone who knows what they are doing. Grey wire from the relay that gets a splice from the oil pressure sensor to send power to pump while running, and that's it. Grey wire in a single loom on the left side going all the way back. Sorry for this terrible news. He should have been able to figure it out by now, or ruled out at LEAST 100 things by now.