[HuckingFigh]

This is my first post on this forum, but I've been reading for a couple years and learned a lot about the 3800 and how to fix problems with them (series 1 and 2 anyway). The problem I'm having is baffling me and a few others as well, so I figured I'd post here and ask for some help.

I have a '99 Grand Prix GT that runs great when it wants to run. Sometimes it will choke up and die while I'm driving, sometimes it won't even start at all. I've replaced the battery, fuel filter, spark plugs and wires, crankshaft position sensor, and the ecu. I've tested the alternator, the coil packs, and fuel pressure and all check out fine.

I'm wondering if it could possibly be the ICU or the security system (damn passlock system). At this point I'm just tired of dumping time and money into it just to end up back at square one. Any help would be greatly appreciated.

Side note: If I posted this in the wrong section I apologize. Sort of new to using this forum.

 

[gtx500hp]

Try unplugging the MAF and try to start the car when it malfunctions.
You may have a flaky MAF.
You may have to install a fuel gauge that you can see from the dash. You have to know if the fuel pressure is dropping off. You may have a failing fuel pump.

A good place to start. I have not heard of an ICM failing intermittently the way you are describing. Clean and tighten engine grounds and re-seat connectors with di-electric grease. Swapping out parts gets expensive. Hopefully, you can rsolve this before swapping out more modules...best of luck on this aggravating problem

 

[HuckingFigh]

Earlier this afternoon I had my gf turn the key for me while I unplugged the MAF sensor first, then tried the o2 sensor as well just for the hell of it and still no luck. I will admit I haven't cleaned all connections but that'll be at the top of my list tomorrow. I'll re-check fuel pressure as well and hopefully I can get something figured out.

 

[HuckingFigh]

Well I went out today and tried to start it and it fired right up. Still haven't cleaned the connections, but I'm about to do that right now.

Edit: Killed it and started it again. Gave it a little gas and it died on me and it won't start again. Back to square one.

 

[paulburke]

have u had the alternator checked sounds to me it is starting to fail it will somtimes fail to charge battery properly then one day bamb nothing batt. dead and no start jump battery she fires right up then bamb dead agian i would have alternator checked at autozone!