CamaroVsMustang

Ok so after trying to figure this out... let's throw some **** into this chung.

the car
97 Camaro SS SLP LT1

icms have been replaced once a week weekly for the last 2 months. so I have already done some heavy checking. I looked for a burnt up wire. 4 Wires run off of the ICM. One goes to ground. One goes to the coil (coil and icm pigtails have been replaced) one wire goes to the ECU and the last one to the CPS.

now i have run through all the harness... and found the only thing burned up were the three wires coming off of the CPS (so cut out 7inches of each of the 3 wires) and replaced with suitable wire, butt connected... and shrink wrapped. but still burning up the icms. replaced the last one right after to eliminate any questionable icm problem. ran 200 miles round trip, some short driving today in hot weather... went home right quick to snap a couple pics... and car went caput... again.

icm is dead...
if i replace it... i know the same thing will happen again after i eliminated all the wiring possibilities... so can the heat transfer from heat off of the head be eating these things up?

i got the spacer mod... about 2 inches off of the head... but i still notice the heat transfering through to the icm bracket. so does anyone think that the heat is killing the icm... or should i check elsewhere.

if i check out the icm (oriellys said a unit was bad right off of the shelf) they will say its bad. autozone doesnt have a tester... advanced auto?

but phsically i have checked the heat coming off of those bolts... and it just seems to me that heat is now the culprit. last thing i can possibly do is run a different ground. but i dont believe the ground is at fault. i believe the ground is tied in with several other grounds... like injectors... ect ect... any help will be awesome. also usually after the initial burn... round town driving can usually smell a rich running condition.

if i replace the icm... it will run fine for about a week... then same issue. ECU has been phsically checked. nothing burnt as far as the eye can see...

any and all help would be much appreciated...

might try to relocate the icm and coil to the driver side fender well.

thanks

CamaroVsMustang

so heres another twist...

just took the car to advanced auto to have them check the icm. the one off of the car tested good... (its literally across the street from my work)

the new 10 dollar one from ebay (backup just in case) tested bad right out of the box. so back to square one again. so im thinking the heat is eating these things up. so im thinking of relocating the icm. see if that helps. ill continue updating.

Spartan7

iTrader: (7)

You're reading your diagrams wrong. That would be 12v ignition voltage SHARED between the ICM and CKP.

You mentioned a cheapo ICM. Is that what you've been burning up? Everything other than a Delco is a crapshoot as far as quality and longevity. Are you using the stock heatsink? Did you apply the grease that comes with the ICM?

Have you verified continuity and checked resistance of all your repaired wiring?

shbox

You had burnt up wiring to the CPS? Did you find out why? Even stock location ICMs don't burn up like you say yours is. Sounds like an electrical problem you have not found.

Paul Bell

iTrader: (9)

I'm thinking somewhere else in the engine harness there's a faulty ground and it's completing it's path through the ICM wiring.

CamaroVsMustang

well according to the diagrams... the 4 wires coming off of the icm go to 4 different places.... according to the wired diagrams.

1 goes to coil
1 ground
1 cps
1 to the ecu

tracing those wires... according to diagram... well they fit exactly where they are suppose to be/go according diagram.

dont know how im reading that wrong. maybe we should write to haynes and tell them...

CamaroVsMustang

the cheapo is used as a backup... just in case im out in the middle of no where. heat sink is stock. yes grease is being applied everytime. ive bought several different brands of icms... oriellys and autozones. bwd... well i would put that before delco on some of their stuff. as for checking continuity and resistance... they've been checked and putting out within specs

CamaroVsMustang

yeah shbox... the wires burnt up off of the cps were because of the wires had sat on the headers at some time. sorry i didnt put that in there. as far as the 4 wires coming off of icm all had been traced, and the one running to the cps was burnt and found the 3 off of the cps burnt up, prolly grounding out to the body at some point too if not only the header. but im leaning towards excessive heat transfer to the icm.

im going to try mounting the icm and coil to the driver front fender. unfortunately finding places to accurately test these suckers seem far and few between. (icms)

after sitting for 10 mintues running at idle... i wonder if that heat is what is killing it. seems to be running well again. most of the the sensors have been routinely replaced. most of the days im having problems are high heat days 100 degrees. if after this isnt working... i dont know what to do.

CamaroVsMustang

im thinking of regrounding the icm when i relocate it... somewhere nearby... and reground the ground somewhere off of the head. its all a test in progress...

SS RRR

iTrader: (2)

Didn't read the entire thread, is the ground strap present?

94LTZ

iTrader: (5)

I killed a couple off these but not near as fast as you are, my last on I just plugged in the harness and let it hang, never had a issue.

I wonder if the coil or something it sends a signal too could be some how be killing it?

CamaroVsMustang

yes and is grounded to the head

CamaroVsMustang

i replaced the old one (coil). had a duralast in there. then when i started picking up the problem, i went msd.

the problem persisted with driving around town. literally every weekend i could count on my icm getting toasted. i usually would go crusing around town. speeds ranging from 25-45 mph. i even went out of town a few times, ranging from 150-300 miles. and thats when a icm would burn up.

i would turn off the car, park it, raise the hood, and the heat coming off of this thing, just was wow. thats with the 1.5 inch spacing. im trying to make it from nevada (im in kansas) to see my grandparents. and my 6 year old daughter is coming with. but if i keep having ignition issues... well that could put a delay on things.

well im off to move the icm and coil...

SS RRR

iTrader: (2)

Do you mean from the chassis to the stud that mounts the coil, like it is stock or do you have it bolted down somewhere else on the head?

CamaroVsMustang

Yes from chassis to the stud on the head... stock location bolted down ground strap

Spartan7

iTrader: (7)

You're explaining it wrong then. Does that sound better? The pink wire going TO the ICM is 12v switched voltage FROM the fuse block. This same circuit is shared by the CKP, i.e. the pink wire also goes FROM the fuse block TO the CKP (and also the coil). It is not a signal wire, it's just positive voltage.

I have been running the ICM in the factory location, unspaced, for years, and have yet to kill it (an AC Delco ICM just so we're clear). That's why I asked the questions I did about the heatsink and grease. I agree with Shoebox, you should not be burning them up this quickly even in the stock location.

Paul Bell

iTrader: (9)

Just for reference (thanks Shbox!):

http://shbox.com/1/1996_ec_03_ign_system.jpg

CamaroVsMustang

Looking at shboxes diagram... well thats pretty much what ive been saying from get go...

Lets recap... didnt say anything about pink being positive/power wire... i just said the following

One wire (green) goes from icm to coil
One wire (white) goes to pcm/ecu
One wire (pink) does go in a loop... connects to CKP (which does run power to the 3, icm, coil, and CKP
And lastly black... ground.

So maybe u were misunderstanding what i was saying.

Which was i checked... all wire traces...from icm... going to CKP...

Which the 3 wires running from CKP were burned via header... via possible grounding out through the body/header/or other wires.

Which one of those wires (pink) was positive power shared through the coil and icm. Then u have yellow... which is CKP sensor signal... running to pcm... then pink/black reference low... which goes from CKP then ties into pcm, and optispark... so...

Still heat could be an issue... but we will find out.

I agree... these things shouldnt be burning up (not literally) just the fact that they were getting so hot that icms were failing. Which is a perfect theory that they were grounding out. Causing the icms to short out.

So next... fuel pump just ate it today. So... in a few days i will update....

myltwon

iTrader: (1)

Well I've had bad wiring at a the fuel pump relay under the dash cause fuel pumps (240lph) pumps to burn up left and right. Fixed it and haven't had an issue since, not sure if this is tied into the ICM at all but could be related.

hagff95

iTrader: (1)

Of course if you burned the wire replace it but if you space it on the fender it may work but make sure it's grounded well also if you keep it on the head use only one washer and get thermal compound from like best buy for 10$ stuff they use for cpu's and apply a thick layer. When you space it to far away from the head it's harder for the heat to escape from the icm which burns it up twice as fast there are a few threads on here and similar forums that explain it better but I went through 4 icms in two weeks bcuz I used a half inch nut on each bolt