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ICM Problems??

02BlueGT

02BlueGT

New member
Could a bad ICM cause a rough Idle, but not cause problems elsewhere? Cause I've eliminated most other options, and before I go invest in a new ICM I'd like opinions if it could f-up the idle only.

The car runs fine at any engine speed above 1300 rpm, in the 900 - 1250 rpm range there is a slight miss, and at idle it is rough, sometimes even stalling out, new plugs, swapped out the coils for a new one, no change... eliminated all other options than a bad ICM or possibly a screwed up PCM
 


I dunno, the ICM would not be my first thought in that. Its not unheard of that they go bad, but its not all that common either.

Dont get me wrong, its entirely possible, but with a rough idle and stalling, I would be looking more in the direction of the IAC, MAF, that sorta thing. Just because you didnt mention it, and because you've changed the plugs and coils, might be worth looking at the plug wires. Though even those wouldnt pop to the top of my list.

Are there any codes, SES light on or flashing or anything like that?
 
Ive tried all sensors and none are causing the problem, I have no ses light,(other than when I was checking sensors) I am running out of ideas on what it could be hence why I'm looking at icm, Like if it has an idle circuit in it or something that is bad.... but now that I think of it,a open in a spark plug wire may cause this... but it isnt constant.... this one is a real head scratcher:(

I'll give you a call this week if I need and thanks for the offer schlim
 


Yeah, the cables have less than 8k as did the plugs, but plugs were cheap, and old ones were a heat range colder and with all my short trips got pretty fouled
 
i'm in the garage today (well after i get a couple hours of sleep!) eric and I got several of the aluminum pieces bent for the new massive whipple TB plenum ( said the hell with it and it'll now put the TB ~1 ft behind the drivers headlight...good fer the track too:cool: )
 
Yeah, I'm gonna try to clean the contacts in my ignition switch, maybe it is causing the problem, cause sometimes it seems like the power steering is a little screwy
 


14.75volts solid, 3 month old battery, just cleaned the terminals.... My ignition switch was carbon-coated... but I still have my problem
 
But my Alt, may be outputing a low current, I just don;t have equipment to test it I.e. an inductive amp meter
 
When I turn on all accesories, Ac on 5 and rear defroster on, radio on, headlamps on, the car acts the same, so it must be ok..... I think I'm gonna try some seafoam tomorrow and maybe injector cleaner we will see
 


02BlueGT said:
When I turn on all accesories, Ac on 5 and rear defroster on, radio on, headlamps on, the car acts the same, so it must be ok..... I think I'm gonna try some seafoam tomorrow and maybe injector cleaner we will see
Click to expand...

get it tested anyway, it's free, turning all the accessories on doesn't give a constant load like you would think
 
might as well get it tested for current/voltage under a carbon pile load...just to be sure.

for the injectors, get yourself some new Orings and pull the rails off. disable the coils (i usually pull the coils and leave the ICM plugged in) flip the rail over and reconnect the inj clips. have a friend crank the car over and look at your injector spray patterns, if you find anything funky, remove the inj connector and clip and flip the inj around (one at a time) reconnect the wires and crank it to try to backflush the injectors, for the most part its a 50/50 shot as to whether that gets rid of the crud that could be causing a streaming injector, but its cheaper than just sendiung them out to be cleaned.
 
I think I just need to buy a top swap, and replace everything :)....I need to drive it now that the ignitio0n switch is clean, the pcm may need to relearn???... I am leaning back towards vacuum issue, cause the needle is very shaky and moves between 19 and 20.5 inches
 
did you remove and plug the evap purge solenoid? small changes like that could just be the system purging the vapor cannister.
block it off at the TB and retest vac

gonna get trannymans setup?:D
 
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