I have a 96 Tahoe 5.7 with 94k that when taking off fairly hard or even when in park and press the gas with some authority will be rough or sputter for split second(usually before it gets past about 1200-1500 rpm's)then its fine.And if you accelerate gradually or press the gas lightly it wont do it.Thing is it only does this when driven for a while and really warmed up.When i first start it and before it gets up to operating temp it revs like a sports car no roughness sputtering at all!Any ideas what this could be!Also sometimes when reved hard i hear slight popping from the exhaust(don't know if its related or not)Any help would be great thanks!

Sounds like a fuel problem. I would check the pump, it may be going bad. Usually a full tank of gas does a good job of cooling the pump, and when gas is low, the pump gets hot and a bad pump could act up.

I never experienced what you have in the sense that your truck is still running, however, I had the same symptoms and no more than 10 minutes later my car wouldnt start, and a new pump fixed it.

yeah i was thinking the same thing too among other things.But the truck starts right up!So that was throwing me off a little.

Check your fuel pressure. It should be 60-65. If not the fuel pump is going out.

Yeah, just because it starts right up, doesnt mean that the fuel pump is not going bad. Have it checked.

Thanks!I will have the fuel pressure checked!Also do you think it could be a clogged cat or bad 02 sensor!

If the Cat. was clogged you would smell something that smells like rotten eggs. The O2 sensor would give extra crappy gas mileage. You would be getting about 8mpg or less if the O2 sensor was out.

I am really starting to lean towards the fuel pump!Even though i am not losing power or getting any hesitation in the mid to upper rpm's!I know this pump must have been in this truck for a while cause my gas gauge is all over the place.And if i am correct its all one piece GM calls a fuel pump module.For all i know it be the original pump.i only had the truck a month.but i doubt it since i hear these trucks like to go through fuel pumps.I guess when i check the fuel pressure i will know for sure!

Mr RICH1223!!!

You've described my problem exactly!

What did it end up being???

CHeers


I am really starting to lean towards the fuel pump!Even though i am not losing power or getting any hesitation in the mid to upper rpm's!I know this pump must have been in this truck for a while cause my gas gauge is all over the place.And if i am correct its all one piece GM calls a fuel pump module.For all i know it be the original pump.i only had the truck a month.but i doubt it since i hear these trucks like to go through fuel pumps.I guess when i check the fuel pressure i will know for sure!

I am really starting to lean towards the fuel pump!Even though i am not losing power or getting any hesitation in the mid to upper rpm's!I know this pump must have been in this truck for a while cause my gas gauge is all over the place.And if i am correct its all one piece GM calls a fuel pump module.For all i know it be the original pump.i only had the truck a month.but i doubt it since i hear these trucks like to go through fuel pumps.I guess when i check the fuel pressure i will know for sure!

In case you don't know, plugged (or partially plugged) fuel filters shorten the life span of a fuel pump.

ok, thats what i thought to.. but keep in mind, down here in australia we've been fighting the fuel prices for years with 40% of the population running our cars on LPG (Liquid petroleum gas), i believe you guys refer to it as propane.

So, our cars/trucks are duel fuel. Gas tank (petroleum) and a gas tank (liquid petroleum)

There ain't no spark on LPG either.... i did change the fuel module almost a year ago... but throughout all this crap, the fuel gauge is going silly.

the fuel pump still switches on for a second when you start the car on LPG, and if its not working, could it be sending a "no-go" signal to teh computer, who in turn, won't supply a spark???

cheers,

Dion

In case you don't know, plugged (or partially plugged) fuel filters shorten the life span of a fuel pump.