87 GT, Auto, Stock. Driving home tonight (50 mile commute 90% hwy) running about 65mph. 2 exits from the home stretch. Car loses power. start droping to 40 mph. Let off throttle feather it a little no power let off throttle all the way, some power returns than start sputtering like I have no gas or lost spark still able to drive no loss in electrical power. Get off the exit ramp and cost to the stoplight and car acts as if nothing ever happened. Another 10 miles home and she drives perfect. Not one sputter at all. 2nd time it has happened. last time about a week ago. It seams when it starts I lose engine power. Let off gas, coast a little, stop at light. hit the gas and everything seams fine. Coil pick up? I.C.M.? fresh tune up 5k miles ago using all GM recomended parts. No cheap S#!t. Been driving lat 8000 miles with out a single hick up. Any help would be great Thank You in Advanced.

That's one of the ways the ICM starts dying. No codes, no warning, just starts acting up and within days you find yourself stranded on the side of the road.

Thanks Bloozbery. I will change it first thing in the morning.

i vote that you carry a new ICM and the tools to replace it.

Be sure to put a coat of heat sink compound between the ICM and the distributor housing, not the dielectric grease that some provide with the new ICM ..you can get a packet at radio shack

ICM is most likely. Just another thought, fuel filter or strainer int the tank.

JUST a thought too... if the ICM isn't the problem (although this is my guess as well), it COULD also be a clogged or melted catalytic converter.

I've had this happen a couple of times. Sometimes you'll hit something and the cat will break apart and clog itself. Other times, the cat will get so hot (either because it ran lean, or you put too much seafoam / BG44 on a not totally full tank) and the cat will melt. In this case, you won't hear any noise, the car will just suddenly lose power. In my case... I had a TwinCam 97 GrandAm. The car was driving fine. I was driving home on the highway and the car just drove spectacularly... smooth as can be, 30+ miles to the gallon, etc...

All of a sudden, the car started to lose power... it was a struggle to maintain speed. I made it another couple of miles, but the car hesitated and studdered.

I could not restart the car. After it cooled down, I was able to start it, and it would idle (although poorly). Giving it any gas at all, and the car would sputter and die.


I assumed all the same stuff everyone else did... fuel pump, fuel pressure regulator, TPS, you name it... I replaced it all. The only thing the ECM (OBD-2) said was "Multiple Spark Misfire".

Ultimately, I sold the car for $1,500 and said it was mechanically good, but that there was a problem with the fuel delivery.

The new owner was a mechanic and actually pulled the engine when he realized that the catalytic converter had completely melted inside (the forward cat that connects directly to the exhaust manifold). Needless to say, he was happy, but pissed that he had pulled the motor only to find that the cat had melted.

So... just throwing that out there that if the simple stuff doesn't reslove itself, double check your catalytic converter before you get too crazy throwing money and parts at it....

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Todd,
2008 Jeep Patriot Limited 4x2
2002 Ford Explorer Sport 2dr 4x2
2002 Ford Crown Victoria LX
1987 Pontiac Fiero SE / V6
1973 Volkswagen Type-2 Transporter

quote Originally posted by Bloozberry: That's one of the ways the ICM starts dying. No codes, no warning, just starts acting up and within days you find yourself stranded on the side of the road.

That is what happened when my ignition control module went out.

quote Originally posted by bristowb: Thanks Bloozbery. I will change it first thing in the morning.

Please keep us posted on whether or not that fixed the problem, bristowb.

quote Originally posted by White Spyder: ICM is most likely. Just another thought, fuel filter or strainer int the tank.

quote Originally posted by 82-T/A [At Work]: JUST a thought too... if the ICM isn't the problem (although this is my guess as well), it COULD also be a clogged or melted catalytic converter.

I suppose yet another possibility is the coil.

As I'd mentioned earlier, I had an ignition control module go out on my Fiero as well. For awhile, the engine would die, but then after it cooled, I could restart it and drive it briefly, until finally, it would just not restart.

However, when my Fiero's coil later failed, the car's engine died once, and it "stayed died," until it was the recipient of a new coil.

What happened was the coil had partially melted, leaving me stranded, because at the time, it was unshielded and close to a large, unwrapped, aftermarket Y-pipe (sometimes called a "crossover pipe"). That was an unusual set of circumstances, so like the others, I'm inclined to think it's a failed ignition control module in your situation (rather than a failed coil). In any case, good luck to you and please keep us posted regarding how you resolved this.

Well I changed it and my GT is running strong. The other thing that I noticed is that it starts up a lot faster. It used to take about 4 or 5 turn overs befor it cranked now 1 turn over and it fires right up. Thanks guys.