Odd little issue I have been having; truck would cut off and start right back up after maybe a second of engine loss. Noticed the gauges would start falling when this happened too.

Tuesday it died going down the on ramp onto the interstate. Would not start, and i tried everything.

She would crank and act normally otherwise, but no fuel pressure, 0. Turning the key all lights worked, but analog gauges did not move when the key was turned.

Now the fun part, after I paid to have it towed home, it started in the driveway just fine. Until it stops starting I don't know what to test. Personally I torn between an ECM and a short in the fuel pump.

Can someone offer any suggestions please?


Thank you for looking.

 

Either the fuel pump is going out (typically engine stumbles under load then recovers if you close throttle) or your ASD relay is failing shut (kills fuel pump, injectors, and coil). OR could be fuel pump relay failing (supplied by ASD relay)

 

For the life of me I cannot get it to fail . Changed the relays (fuel pump and ASD) and checked the fuel pressure, KOEO 44lbs and same during idle (slightly higher when key first turned).

Couple things in my head now what do you think? First, this pump design has a filter/pressure regulator assembly attached to the top, maybe the ride on the tow truck moved floating trash that was blocking fuel flow. Second, maybe it cleared some debris from the fuel pump sock allowing fuel to pass. yea, i know, I am grabbing every crazy theory in the air but I do not want to pay another $125 to get this blank thing home again, but it is all I have.

20 minutes later, engine off, schrader valve removed, and still at 44lbs.

 

Oh, forgot to mention, the timing chain is starting to rattle and for a little while now when i go up hill or over a bridge she will drop MPH. A high rise bridge she can easily drop 10 MPH empty before reaching the top. I would guess timing after the chain heats up enough to stretch a little but I just had this thing running an hour with the A/C going in the driveway (no electric fan) and still going strong. I know it was heated up there.

 

$153 for a Delphi pump, that is less than another a tow and taxi ride to the bank. I could not repeat the issue for accurate tests but was not leaving my driveway to do it either. thank you for your help this far, if you have any further advice i am happy to listen but the ole girl is getting a new pump to go with the new relays. I will be sure to clean out the tank while i am at it.

 

Put the fuel pump in today and tested it with the bed off, 56psi, ran like a new one. I was very pleased. put the bed back on and tools away tried to start it and same thing. didn't show fuel level, oil pressure, battery/alt level, no fuel pressure. no wires are pinched. this is insane.

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only other thing i can think is computer, any suggestions to test that?

 

I'm thinking wiring problem but I will say 44lbs was low so the pump was bad. Tracing the bad wire can take time and a wiring diagram.

That's all I got for ya

 

thank you. just odd. wonder.... ignition switch (key) ... but i have a lot of things to check. thanks for your opinion. need them all at this point.

 

When you tested it with the bed off, did everything in the dash work right? What year/engine?

 

yes everything worked perfectly, bed was 4 bolts out left side 4 bolts loose right side and jacked up. only unplugged the lights on the left rear.

but everything was working after it was unloaded from the tow truck too. before i started working on it. odd.

thanks for the help