Im at wits end with my car! 2002 monte ss 3800 N/A. Random stall! Starts fine after stall. But it stalls at stop lights... turning left only... and coasting, sometimes at a stop with my foot on the brakes the car will lurch forward afted about 30 seconds then die! Can drive on the highway or interstates with out a problem! Throws up no codes! Ive replaced the MAF, AIC, TPS and crank trigger. No change. Some one told me it is the computer! I dont believe it! Its embarrassing to go out with a new date and have it die on me! Sometimes I just want to wrap it around a tree!!!!

 

My guess, spark plugs and wires. If you are near or over 100,000 miles and still on factory plugs, it's time to pop in some new ones. Their spark is not what it used to be to keep the car going.

Also, consider changing your fuel and air filters as well.

Make sure you do NOT use BOSCH plugs (they are typically more trouble then they are worth). Go AC Delco or NGK. For the wire set, I typically use BOSCH or AC Delco wires. RockAuto Parts Catalog is a good place to pick up these parts.

 

Yup! Did all that too, plus air filter. Car has 125000 miles on it. I love the car but this issue has got to stop!

 

I assume you are not using Bosch plugs?

I know you mentioned replacing the MAF. Does not mean the new one was good. With the car off, try unplugging the MAF sensor and driving it. Yes, it will pop on a Check Engine light, but the PCM will attempt to substitute values for the MAF and the car should continue to run. If you don't have the problem, change the MAF again.

Now, just grasping at straws, have you had the catalytic converter checked?

Also, what about the upstream O2 sensor (on the rear manifold)?

 

Something you said started my old gears working. I had a similar problem with my Blazer. Turning left, stop signs, foot off the gas peddle cruising up to a stop sign. Turns out it was the fuel pump. It happened more often when it was below half a tank. Can't say for sure That's your problem, just that the symptoms are the same! Good Luck!

 

Good Point JC!

So, be sure to check the fuel pressure on the fuel rail.... Theres a Schrader valve that's easily accessable.... Your local auto parts store should have one you can rent...or if you have a friend with one... youll be all set ! That way at least you can eliminate a fuel pressure issue...

Thanks JC and Jason!

 

I have read a few things about a ground next to the ecm. Could that be the problem?

 

Checked the ground by the ecm ground off the paint and regrounded it still has the same issue

 

PCM issues are pretty rare... Unless the ground point was tampered with OR corroded.

As mentioned, a fuel pump issue could be related. You could pressure test the fuel pump at the fuel rail. I'm sure you can do a loan-a-tool from the parts store.

Have you tried the MAF unplugging suggestion I provided? Looked into issues with the CAT? When the car is stalling and having issues, get somewhere safe and look under, see if the cat is cherry red, if so, that is certainly a problem.

Also, the upstream O2 should be replaced every so often due to the heating element breaking down. This has a direct effect on fueling. Even if it does not solve the issue, it could be a step for god maintenance.

 

The other night coming back from my sons football game (with new girlfriend embarrassing)i decided to get gas. I pulled to the pump got out and started refueling. The car died as usual! I finished filling up my car and started it up. It ran like it was dead on a couple of cylinders! The check engine started flashing and was starting to smell bad. Now i just drove 35 miles and had no issues what so ever! I limped it home and threw the scanner on it! I got a p0300 code. I looked under the car and seen the cat was cherry red! So i shut her down and looked at it the next morning. I came up with the ICM was bad and changed it out! I thought great! The stalling issue should be taken care of ! Cleared the codes and haven't had any more come up. But the stalling is less frequent now but still intermittent!
So here is a list of everything that has been changed.
ICM
TPS
IAC
MAF
COILS
WIRES
PLUGS
O2'S
EGER
MAP

Any ideas would help PLEASE!