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Alright guys, I'm going to try to provide as good of a history as I can here. About three years ago, during my deployment to Iraq, my 2006 base Grand Prix threw a code for the crank sensor, which was then replaced by Calvin at the craft shop on Fort Knox. About a year later, the issue came back, this time without the DTC. No MIL on, no hidden codes...no warning. The car would shut down while I was driving. Headlights worked, radio, fan, internal accessories worked. After it killed, I'd get a hard crank from the starter, but no turn-over. I'd have it towed, and upon its arrival at the dealership, it would start and run like it was new, so the techs told me they couldn't help me, due to the fact that they couldn't induce the symptom again.

After breaking down once, in a frustrated "I give up" moment, I happened to lean against the engine, with my hand on the coils, and almost burnt my hand on the lowest coil pack on the module. At the time, I'd installed three MSD Blaster II coil packs, but deduced that one of them must be replaced, so I replaced all of them with the least expensive Duralast coils I could find, but all brand new. Still wouldn't start. Had the ignition module tested, tested bad, and I replaced it(again, Duralast). After repeating all of the above roughly five more times with new modules, I decided to invest in a dealership's expertise. After eyeballing the idling engine for a bit, the tech at the GM dealership poked the cam/crank sensor/ICM wiring harness(through the spinning belt, while it was running!) with a long flathead screwdriver, and the car started to stall. They determined that Calvin(Fort Knox craft shop) had inadvertently tucked the harness under a ridge on my water pump, thereby stressing the connection and causing it to short. After about $400 and a new section of my engine's wiring harness, all was well. For about a year and a half. Now it's doing it again. It's blown one(possibly two, I haven't had this one tested lately) ICMs, and under the advice of a GM service manager, under process of elimination, using every bit of logic I have, took an afternoon and replaced my crank sensor. Fired right back up, and ran strong for over an hour. A/C on high, radio on. Decided to take it for a drive...and within a mile from home, RPMs dropped, I lost power steering going 45mph. Rolled into a small neighborhood...where I, frustrated, randomly started jiggling wiring harnesses and knocking on sensors. Engine fired back up, and ran for about a minute. Killed once more. Waited ten minutes....started it back up. Ran for five minutes. Killed again. It's been doing this for the last two weeks, and quite frankly I'm getting tired of having to get toted around Louisville, to and from work by everyone because my Pontiac just plain won't keep running.

I do, however have an idea. Not ONE SINGLE TIME, while replacing the ignition module, have I cleaned, brushed, or prepped the mounting surface for the new ICM. I did apply the white grease to the back of the module, but there's old grease, and quite a bit of dirt and light corrosion on the plate the ICM's mounted to. Could this be causing ALL of my problems? Today, while on lunch at my work(the Pontiac's parked there, because that's the last place it broke down), I tried starting it ten times. Nothing. Got out, gripped the ICM connector and the bottom of the ICM, tried to wiggle it pretty stiffly, and the car fired back up instantly. I repeated this same process four times. The ICM isn't loose...but attempting to wiggle the assembly seems to kill and/or fix my car momentarily.

HELP!
 

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My Park Ave Ultra would do that, just die while driving, did it several times, I couldn't nail it down. I am the type who won't throw parts on it guessing. I have to know what it really is.

Finally one day it died and wouldn't restart, left my wife stranded.

Fuel Pump. I wasn't able to troubleshoot it until it was dead.

What I found on post mortem inspection, the fuel pump's brushes were shot, just plain worn out. 180k miles or so.

So take a look, grab a fuel pump from a 91 Chevy Syclone and toss it in. Cheaper than a fuel pump module, and is the pump that can easily handle the 3800 SC.
 

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Discussion Starter #3 (Edited)
I'd thought about the fuel pump, but how could I get the problem to repeat by wiggling the ICM? I always have good fuel pressure, never really any spitting/sputtering...is there a way to check to see if my fuel pressure is just "low"? Plus, I just rolled over to 100k about a month ago.
 

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Everytime I tested fuel pressure, it was good, but it would randomly die on my wife and son driving it, only 1 time with me, and that was on a decel. Decel is the easiest time to die if low pressure.

I guess I don't see how you could wiggle ICM, mine is mounted down with 2 large bolts. It should not wiggle. In my car there is 2 grounds in the vicinity, one just under the ICM, likely to the ICM and one just below that on the block that comes from the injector wiring harness (not to the injectors, just where it goes)

What kind of car is it? I think the only way you can confirm fuel pump with the situation I had (reading the forums, is somewhat common), is to have a high current low resistance resistor (say 10 amp 1 ohm or less) in series with the pump and measure current draw, the moment the current drops, the pump is stopping and not working.
 
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