so here's my problem (LT1)

I have a 1995 Z28
MSD coil (one year old)
EBay Opti (8 months old)
new autolite 103's (the car has a bottle on it, but i'm too afraid to spray it with these ignition problems)


The problem is after i have driven the car for any distance after it has reached normal temperature. If i stop to eat, go to the store, work out, etc (anywhere between 30 min and an hour), basically anytime the car does not cool off completely. The car will misfire, sputter, stall (if i let it), and run on what feels like 5 cylinders (maybe exaggerating but it runs BAD)

this problem will go away after a few minutes, sometimes as little as 30 seconds, sometime as long as 5 minutes

also, i have been having trouble with the car knocking a little bit, and idling really rough

i am still thumbing through all of the ebay opti threads trying to figure it out.


btw, i have gone thorugh shoebox's page and done the voltage testing, i got less than 1 volt at the ICM and every time i chase up to the coil, it pops the ignition fuse so i dont know.

are there any other tests i can do by myself, i dont feel like throwing parts at this thing and hoping for the best anymore. its too expensive and very frustrating.


thanks again everyone

I had the exact same problem. If it sat for 30 minutes to an hour it would run bad if it was still hot. I had the car die on me several times and changed the icm and its been fine every since.

i've replaced the ICM about a year ago. hard to believe that it has gone bad already.

how would i go about testing the ICM?

so, the coil was loose

but now it is throwing a code every once in a while. the trouble is, we can't get the laptop to make a connection with the pcm.


using datamaster and freescan with no results.

What cable and connector are you using to attach to the 16-pin connector used in the 95's?

we got my old school laptop with a serial port to work. something about the USB to serial adapter doesnt work with the newer laptop. but i got freescan to work. it only reads codes that are being thrown at that time it seems. not codes that are stored.

datamaster won't run on the old laptop bc there is too little memory, lol