hardwarz

OK, I have a 99 Tahoe with a 5.7l, 4x4 4 door. I just replaced the fuel pump about a month ago. Now every once in a while the car won't start and I have to press down on the gas pedal for it to stay running. If I let off, it dies. After a few minutes of trying to restart, it'll be fine... maybe for days, maybe for hours, maybe for just a few minutes.

This morning and a couple times this afternoon (for a total of 3 seperate times) while trying to start the Tahoe, the car won't even click over. After turning the ignition off and back on, it will reset the computer (best way I can describe it.) Radio powers off, doors lock, dash flashs on. Try it again and it'll crank. It may not start (have to hold down the gas a bit) but it will crank.

Any ideas?

Hardwarz

MalibuMaxxSS

the ruff running maybe be something simple like plugs or fuel filter....the no cranking ....dead spot on the starter.....?? dont know on this one could be ignition, if so could be the source of the ruff running aswell...

ZX1100F1

Sounds like the motor is starving for fuel or air; most likely fuel, does it smoke when it starts? If you have a fuel pressure gauge take a reading at the rail and make sure that you have at least 50psi.

I have seen stuck EGR valves casue similar problems, so check this out as well.

Or you can unplug the vacuum hose going into the fuel pressure regulator (driver side fuel rail) and see if there is any fuel in the hose indicating a faulty diaphragm; it is common for this part to go out after several years.

If a fuel injector has a deposit build-up the popet will not seat properly and will mis-fuel the cylinder and cause a hard start and rough running motor, you may want to dump a bunch of fuel injector cleaner in a full tank of gas, Techron works best and put 4 or 5 sixteen once bottles in one single tank of fuel and run it out.

It probably wouldn't hurt to clean out the intake with a spray can of fuel injected engine intake cleaner.

You don't mention how many miles you have on your 99 Tahoe?