Every summer our 2002 suburban does the same thing till fall when it stalls at idol at stop light, drive through fast food places. When the AC is on for some reason she will idol for a few seconds then die. Cranks right back up each time but will continue to stall. So far I have cleaned the throttle body and changed the air filter but not much else. Any ideas what that might be?

 

Check your fuel pressure PSI

 

I did replace the fuel pump a little over a year ago but it wasn't a OEM pump. It looks like the fuel pressure should be in the 48-54 psi range? If it's to low should I start by replacing the fuel pump or are there other factors?

 

With an MPFI system, optimal PSI is 60. 48 might be too low. If you have a replaceable fuel filter dump it. It might also be your fuel pressure regulator.

 

I checked my fuel pressure tonight, with the key in the first position and not started I have 60 psi but when I start it drops to about 53. My fuel regulator was replaced last year and it doesn't leak any fuel when I take off the hose.
It never struggles to start up when it's cold or even after it stalls.

 

53 PSI should be fine, but it all depends. Some vehicles are finicky and some are not. I checked the range online and it showed 55-62 PSI, but 53 PSI is very close, and the gauge might even be off by a few pounds too. The only other thing that I can think of would be a fuel injector problem/issue with your Chevy.

Might be time to clean the MAF, but highly I doubt that's your issue, its just that they can go bad or get dirty without throwing a code. I'd go with the fuel injection issue as a probable cause for your engine quitting on you at present.

 

Is it normal for it to idol at between 500-750 RPM, or is that to low? Thats where it idols all winter with no stalling problems. What would be a start to address a possible Fuel injectors problem without replacing them individually?

 

500 rpm is low, should be 750 (aprox). Low rpm is usually caused by fuel pressure regulator, I know yours has been replaced, but look at the fuel quality, have you got fuel from a source that you haven't before?

 

I just checked to see if it's throwing any codes and there is one. It's P0118 which is a engine coolant sensor. It's a cheap part so I'm going to get it today and see if that helps. Im also going to get another Fuel pressure regulator and see if that helps.

 

I have an 02 Tahoe , for several months it's been acting up when hot outside . I chaulked it up to bad gas until about a week ago when it just started shutting down everyday. Most of the time it would crank right back up but a couple times I sat for a while on the side of the road before it would crank . Tried several things before finding this page and after reading everyone's posts I decided to get a fuel pump . And it was indeed the problem.
Runs great now .