wallyburns

I won't bore you with all the attempts to solve a misfire at idle and on acceleration and random failure of the ignition control module. You can read all that in other posts on this board concerning ICM failure. The cause, in my case, turned out to be intermittent short circuits in the distributor. Let me explain as best I can. There are two wires coming out of a coil of wire that surrounds the center post of the distributor. I believe the part called a reluctor rotates inside that coil of wire. At any rate we all know there are two wires from the center of the distributor that plug into the ICM. At the point where the two wires are attached at the center of the distributor, there is a small plastic attaching piece that has two slots where the wires are held in place. In my situation, the two wires were pulled down out of the plastic grooved holder they are supposedly pinched into and were touching a metal edge of a part of the distributor just underneath the wires. When I finally pulled the distributor and looked at the wires, I had to look underneath them closely and sure enough, the insulation on both wires was sliced cleanly. As the insides of the distributor moved around, the wires, one or the other or both would short out randomly. That's it. After changing the ICM, fuel pump and fuel filter, spark plugs, cap and rotar, plug wires and a number of sensors, even increasing fuel pressure from 10 to 14.5 lbs., with a rebuilt distributor installed the engine now runs perfectly, like it did seven years ago when I originally installed it into my Volvo 262C Bertone coupe. I hope this helps another lost soul out there. I suggest it might be best to pull the distributor first and make sure those two tiny wires are serviceable before you start all the rest of the craziness I personally went through and I also read so much about on this board. Just a thought, and I hope this post helps someone.

Supervisor42

Well, that's a mighty fine first post! Welcome to the boards. Sounds like a chapter in my book titled: "Lessons Learned the Hard Way". I encountered that problem once in a big cap HEI in an old caddy. I was fortunate in that it wasn't intermittent. It would have no spark and after it cooled off it would start, immediately die and again have no spark. The bushing at the top of the shaft had gotten dry and spun the pickup coil around smashing the wires into metal.
Ain't this fun?
(SBC in a Volvo, sounds like the only fun Volvo I ever heard of)

Damon

Yeah, and that's not even the weirdest stuff I've run into. Years back I decided that when I run into intermittent distributor problems with a small or large cap HEI it gets yanked and a new unit gets installed. I keep known-good spares of both types in my garage at all times. When I have a possible distributor issue I drop one of them in and drive it for a while. If the issue goes away and stays away, the old distributor goes in the trash and a fresh one gets dropped in. Fortunately, they're reasonably cheap. Especially if you use junkyard units like I usually do.

BugsyML711

wallyburns,

i know this thread is 5 years old but in the event that you may still get this reply, i wanted to ask you about how the car was running at that time. i think i may have the same problem but before i start tearing it apart i wanted to see if it was similar.

first, it'll barely start, i have to give it gas in order for it to fire up and even at that it struggles to get up to a decent idle speed. Second, if i sit there with my foot on the gas, the rms will vary. it won't stay put at whatever rpm i rev it to, it'll rise and drop after a few seconds. it wreaks like fuel, i think because it's misfiring so excess gas is not getting burned off. while driving it starts dropping off in power and i have to give it more gas to get it back to where it should be. does that sound like what your car was doing?

servo2055chevy

I'm having the same issue

servo2055chevy

I have to treat the car like it's carbourated. It only starts while I pump the gas at the same time if cranking the engine