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Re: I got one for you.... 1994 3100 engine stumble

Posted: Wed Aug 10, 2011 10:07 pm
by DTMAce
I think that is one reason Barry suggested swapping the coils. Could have one shorting to ground or something. I never did get time to really touch the car today, haven't been anywhere. Been in the office, either on the phone, in the base taking things apart or fixing a computer. In fact I have to get back to one. I did do some more reseating of cables on the top end. Haven't done my ohm test, haven't pulled the lower crank sensor connection jon suggested. Ugh.

Probably have to jack it up, pull the plastic covers to get at that one. Not fun.

Re: I got one for you.... 1994 3100 engine stumble

Posted: Fri Aug 12, 2011 8:31 am
by 3X00-Modified
DTMAce wrote:I think that is one reason Barry suggested swapping the coils. Could have one shorting to ground or something. I never did get time to really touch the car today, haven't been anywhere. Been in the office, either on the phone, in the base taking things apart or fixing a computer. In fact I have to get back to one. I did do some more reseating of cables on the top end. Haven't done my ohm test, haven't pulled the lower crank sensor connection jon suggested. Ugh.

Probably have to jack it up, pull the plastic covers to get at that one. Not fun.
I can reach mine from the top, but obviously ONLY when the motor is cold... way too much hot stuff around there.

Re: I got one for you.... 1994 3100 engine stumble

Posted: Fri Aug 12, 2011 9:30 am
by DTMAce
Stupid thing fixed itself yesterday. So at the moment its running normally. Fucking hate computerized electronic bullshit on cars. More I mess with it, the more I'm convinced its some sort of loose connection or short or broken connection or something. gently caress is, where???

Re: I got one for you.... 1994 3100 engine stumble

Posted: Fri Aug 12, 2011 9:53 am
by Chad91GTZ
Icm. There's an epoxy like filler inside the unit, that is subjected to wild changes in temperature. Eventually that stuff gets hard and cracks, allowing moisture inside. Causes a problem like you're describing sometimes, intermittently until it dries out.

Re: I got one for you.... 1994 3100 engine stumble

Posted: Fri Aug 12, 2011 12:14 pm
by DTMAce
Drove to the island today, it was fine for the most part, acted up occasionally. As of right now its fine. Got me stumped, that's for sure. OH well. Drive it till it dies I guess. lol

Re: I got one for you.... 1994 3100 engine stumble

Posted: Fri Aug 12, 2011 8:02 pm
by Money pit Beretta
As a side note I read on some site to use CPU heat sink grease on the metal part of of the ICM. This keeps moisture off of it and uses the metal mount as a heat sink. All you do is the samething that you do with the CPU and use a credit card to spread the grease. I have done this to my 3.1 replacement ICM and my 3100 replacement ICM with no problems. I get a little overboard and do both sides.
That may only help you ACE if you replace the ICM, but it may be worth a try.

Re: I got one for you.... 1994 3100 engine stumble

Posted: Tue Aug 16, 2011 10:09 am
by ifixalot
My daughter's 96 3100 Beretta had similar stumble, when she hit the gas, it would bog and or die.
I fought with it and finally it died and the battery was dead. Turns out the large wire from the alternator had
been rubbing on a piece of metal on the engine and it would short to ground when the engine torqued. By sparking a little at a time, it eventually burned through the wire and she didn't notice that her voltage was down. Finally the battery didn't have enough to keep the engine running and it died on the road.
So, look at that large wire coming out of the alternator and make sure that the insulation hasn't worn through and has been shorting. Since you mentioned the clock and radio losing memory, I'd bet that is what you have going on.

Re: I got one for you.... 1994 3100 engine stumble

Posted: Tue Aug 16, 2011 10:20 am
by DTMAce
Already have checked that. In fact its working fine at the moment, seems to have "fixed itself" sadly. Annoying though, as I still have no clear idea of what was doing it. As some have suggested, it could be an ICM or simply a bad ground someplace. If it reappears, I will dig deeper.

Only difference I had is when I got harder on the gas it ran better.