Hey guys i have a OBD2 b18c5. The icm is going bad i believe. I am going to replace it with a spare one i have laying around to see if it will fix it. My question is.

Is OBD1 and OBD 2 ICM different? I am referring to the heat sinks. Because on my OBD2 dizzy i have on now, it only has 1 screw that i can see that is holding the ICM in place. The other ICM i have is a brown color and it has 2 screws on the heatsink.

The problem i am having is for the OBD2 ICM i removed the 1 screw but it is sstill stuck it place. i tried prying it a little with a flat head screw driver lightly but still not moving. Is there external screws holding the heatsink in place?

And lastly is the ICM the same but is it possible to just change the heatsinks?

 

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They're the same.

 

First of all there is a difference between obd2 heatsink and obd1, unless i have a non stock unit. My ICM # is Hitachi E12-303, and it had the screws for the heatsink on the outside of the distributor, the spare one i had was completely different, had 2 screws that went on the inside of the dizzy.

2nd I think i fixed the problem, i took out my ICM and heatsink and i found some oil inbetween the ICM and the heatsink, and some oil around the heatsink area inside the dizzy. I cleaned it out and i just redlined the car to test it out, smooth as a baby now. I think the oil that was inbetween and around the heatsink was conducting more heat so was causing it to run funny.

Could that be the case?

 

Replace that inner shaft seal # NOKBH3888E inside! its very cheap and easy to do! i just did it not to long on my old distributor, you will keep getting a oil leak there causing more issues down the road.

Also put some thermal compound on the ICM to keep the heat away as much as possible.