91 Burb V2500 not getting fuel to the engine, what should be my check list?

[Chacholoco]

So I was driving my burb the other day, was on the gas and it just instantly stopped. No chug, no warning just quit. Coasted it to a safe place. Turned the key nothing. Just got some gas the night before so ruled that out. This is my first GM truck so not all that familiar with what what. I did run through the fuse box. It all seemed good. Got under the hood and looked for fuses and relays but like I said not familiar with the truck just yet. Took the air cleaner off and put some gas in and it fired. Beat on the gas tank. Ended up just towing it home till I could get help figuring things out.

The truck has only about 87K on it. Has a 5.7 TBI. The only thing I have had done major was replace the intake manifold seal and have the fuel pump replaced. But it wasn't like this. It went sluggish and had zero power and ended up being the pump.

I guess my main question is what should I check that I have missed before I tow this guy in? Is there a relay or fuse under the hood or dash I am not seeing. Any other things you would advise for me to check out first. I just hate to take another tow fee if it is something small that I missed.

Any help or direction given would be greatly appreciated.

Best,
Chach

 

[smoothandlow84]

Fuel pump relay/fuse under the dash....do you here the pump priming when the key is initially turned ? My 5.7 tbi would crank, but not fire over...turned out it was a 15 amp fuse that was popped from getting jump started earlier that day. Pull the actual fuse out and take a good look. The fuse is located under the dash next to the steering wheel. If your pump isnt buzzing, its not getting power. Check or better yet replace the fuel filter along the passenger side frame rail. Dirty gas will clog it quick.

 

[Chacholoco]

So I got in the fuse box and found that the ECM B FUSE was blown. It's a 10. Replaced it and it just blew again.

 

[skysurfer]

Same problem in this thread:http://www.chevytalk.org/fusionbb/showtopic.php?tid/167444/

 

[chengny]

After leaving the fuse block, the power lead from ECMB splits into two branch circuits.

The first component on one branch is the oil pressure switch. The first component in the other circuit is the fuel pump relay.

Check the hot wires (that come from the fuse and feed these two components) for a short circuit to ground. The wires to both the oil pressure switch and the fuel pump relay are orange.

First, isolate the leads from the rest of the vehicle's electrical system. At the fuse block pull - or just don't replace if blown - the ECMB fuse. That takes care of the supply end of both circuits. To isolate the other ends of the two branches:

1. For the fuel pump branch, simply pull the relay from it's socket.

2. For the oil pressure switch branch you will probably just have to pop the harness connector from the switch.


Then with the fuse out and the relay pulled/oil pressure switch disconnected, check the orange wires for continuity to ground.

Turn your meter to the audible continuity check position, connect one probe to a good clean ground and the other to any convenient place on either of the two orange wires. Since the branches are common, you can do this at either the relay socket or the oil switch harness connector - or you can just use the load side of the fuse socket.

A continuous beep from the meter indicates continuity.

They should not have continuity to ground - if they do, you have at least isolated the problem. There is a dead short to ground in one of those two branches.

Note: If I had to guess where the short to ground is occurring (if that proves to be the case), I would suspect it is in the area of the oil pressure switch. When you pull the harness connector from the switch take a few minutes to thoroughly inspect the orange wire as it approaches the switch. Grounds do not generally happen in the sections of the harness that is within the loom so concentrate mostly on the exposed section of the orange wire.