I have a 97 Z28 with no spark. I'm at a loss for what could be wrong. I put a new opti on it and it fired up and ran great(bought the car in pieces) as I'm testing and tuning everything I'm doing a test drive down and back it just dies. No spark at the coil, before I replaced anything else I started following chilton, Haynes, and all data steps and nothing quite matches my coil setup. I have a single plug and all three show a car with two on the coil. But I did the best I could with what I have, and determined we'll thought I had anyway that it was the coil so I replaced it and now still no spark. So my best guesses are it's the PCM, wiring or ICM. Not sure how to figure it out and I can't keep throwing money at it. Any ideas?

 

96/97 has a single connector on the coil. Earlier years (93-95) have two connectors.

96/97 wiring diagram, courtesy of Shoebox:

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

Have you scanned it for codes? What brand is the Opti? Did you loc-tite the rotor screws before you installed it?

Where are you checking for spark - at the coil, at the plugs, or both?

 

The difference in the coil connector doesn't make any real difference troubleshooting wise as long as you look at the right schematic. Did you go through the opti troubleshooting sticky at the top of the forum?

 

She didn't throw a single code, with the exception of MAF that wasn't connected. And it ran fine with it disconnected before this all happened. I put a BWD opti on it because that's all I could get short notice. I just took it out of the box and out it on and it ran perfect. Iv checked for spark at the plugs and at the coil and no spark at either. So I put the new coil on and still no spark. I haven't had a chance to work on it since Thursday so today I'm gonna start looking into it again.

 

I put a new icm on and fired right up. Not sure why it quit working but problem solved.