1996 chevy 5.7 fuel problem

Asked by Jun 17, 2017 at 07:51 PM about the 1996 Chevrolet C/K 2500

Question type: Maintenance & Repair

Ok...so for the last month my truck has been
starting hard. Mechanic said it sounded like fuel
pressure regulator and I didn't have time so I had
him put it in. Ran better for a couple of days and
started acting up again. Took it back to mechanic
and it was giving a lean fuel code. Checked fuel
pressure and it was at like 20psi. He said pump was
bad. I just changed the pump and it started
immediately and ran fine. An hour later I had to go
outside so I figured I'd try to start it again. Nothing.
Fuel pressure at 0. Pump will not kick on. I've tried
running a ground to the black wire straight from the
battery. I've tried jumping the fuel pump relay (87
and 30 I believe). Pump did not kick on. Will start
and sputter on starting fluid. I have an MAF code,
but I wonder if that comes on because I tried
unplugging it to get it to start. Also getting both lean
fuel codes and I've had the cam/crank code for 5
years. Anything?

9 Answers


getting away for a second...was the fuel filter replaced???????????

1 people found this helpful.

Running a ground to the black wire? Try running power to the fuel pump.

1 people found this helpful.

Sorry. The black wire at the harness on the frame. Do by chance know which of the three wires I should dump 12 volts on? Fuel filter was replaced about 2 years ago along with the fuel pump, tank, fuel lines, and vaccuum line.


I suggest that you buy a multi-meter and use it to check for power to the pump. You can also use it to check grounds.

lol I'm an electrician. I have a couple of them. My Biggest problem is that I don't know where I should be checking for voltage. There's three wires at the harness, so ground, power, and ?? Sorry. 12 volt wiring might as well be Spanish to me. I'd rather wire a commercial building lol. Also, I grounded the crap out of the fuel system when I put the new tank in a couple of years ago, so as far as frame and body ground at the tank, there's no effing way that's what's wrong.

I have been doing some research and I came across oil pressure sending unit? My oil pressure stays at 0 while the truck is rolling over. Is that normal or does that seem like it might be the villain here?


Low or no oil pressure will not prevent an engine from starting. Perhaps this will help ------ http://www.truckforum.org/threads/fuel- pump-wiring-color-codes-on-89-gmc-1500.16867/


Your truck should have an integrated fuel pump/fuel level setup so one wire would be for the fuel level.

1 people found this helpful.

It's not the purple or black it's the grey wire is the 12v

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