It's been hard to start for months now. most of the time it would take a few seconds for it to start and rarley it would kick over right away.

NOW, I can crank it forever, and it sometimes sounds like it might come close to starting but never does. (my battery is almost dead from trying so much)

*also, car seems to miss a little at very high rpm, and some black smoke exsists.

all of this seems like absense of spark to me. and i know the opti-sparks reputation. Does this sound familiar to anyone????

 

Yes, it does. Do you get any codes? Even if you don't see your ses light, I would hook it up to a scanner and find out. I've never seen the optical portion go without throwing a code.

 

ses light comes on when the opti fails???

 

It didnt on my 94. I'd try diagnosing everything but the opti first.

-Dustin-

 

My car was doing the exact same thing. I replaced the coil, ignition module, and coil wire-problem solved. Pull off your coil wire and inspect the inside of the terminal closely, even if it "looks" new. Mine was so corroded i couldn't get and ohmmeter to register from one end of the wire to the other. Replace the cheap stuff first.

 

Only if the optical portion goes. the cap and rotor, will not set a code.
If you aren't recieving any codes. there is a good chance that it's your cap and rotor.

When it was running. how did it idle. did it constantly bog down at the same rpm or was it random.

 

it actually idled pretty nice, not too much bogging

 

Where is the ignition coil and coil wire?! I have looked forever, it's so cluttered in there.

 

Drivers side head on the front.

 

Ok guys I'm stumped! The car has a bad miss at 5700rpm and a random no start situation. Using Shoebox's site - thank you very much - I was able to find out that the ICM was bad. I replaced the ICM and the coil (was arcing itself to ground). Checked the coil to opti wire and replaced the ground strap from the icm/coil mount to the radiator support, also checked all the grounds on the motor and added an additional ground just because. The only code the car is showing is ECT Ground. The car is a 94Z28 M6. I need to get this thing to be a reliable daily driver as I have a 120 mile round trip to work everyday. It just died on me yesterday on the freeway, luckly for me I was able to get pulled over without any issues and after waiting about 30min it decided to start again without anything being changed. The only thing I did was pull a plug wire to check for spark when it decided to start. Help!! Thanks.

 

Update: Cleared the ECT Ground code. Started the car to do a datalog run. Got about 5 miles from home and it died. No chance to get any datalogging done. Any ideas? Help please as I am now without a way to get to work tonight! Wife needs her car in the morning.

 

Any luck yet?

I could be thinking totally wrong about this but.....

Did you try cleaning the surface (wirebrush) really well, before putting on the new coil.

 

I had the same problem, ended up being my coil wire, looks like u checked that though.

Are you shure that it is pushed down and snapped on the coil and opti?