95 LT1, 95,000 miles. opti is @ less than 5000 miles, and coil is brand new. Some times when I try to start my car it just cranks and cranks. some times it starts right up. some times it starts, runs for 10 seconds and dies. I have good fuel pressure, I did shoebox's tests on the ICM connector. Im getting between 1-4 VAC on the white wire, and 10+ VDC on connectors A and D. When I disconnect the coil wire from the opti, and have someone crank the engine, Im not getting spark. Ive tried switching out coils with a known good coil. still wont start. I want to know, if Im not getting spark out of the coil if the distributer can still be bad? Im not that good of a mechanic, and I dont have access to a scan tool. can some one tell me where else I can look? I also have an MSD digital 6, msd blaster coil, and MSD window switch which have always worked fine, and the led on the side of the digital 6 when the key is in the ON position with engine off, is solidly lit, indicating no internal fault. every thing with the msd is correctly connected.

EDIT: now its started and running smoothly (no misses). can the optil work intermitently? I don't understand whats going on. there are no service engine lights on.

 

can you try it without the msd box connected.I had one go bad on me before.

 

Sounds like it could be an Ignition switch. do your gauges go out when you try to start the car? Will the car start and then die, and run funny when it does start?

 

Tried it with the msd disconnected, same problem. yes to the second post, it runs, dies and says check gages. but it runs pretty smooth when it does run. the problem is getting worse and worse. it stays running for less and less time. before it would stay running until i shut it off, but now it dies. Ive researched alot of old threads and tons of people have had similar problems. I understand there are several things that could cause these symptoms but unfortunately not very many people followed up their posts with what they found out to be the problem. and I noticed there is a check engine light lit while Im cranking the engine. I don't know where I can rent an obd 1 scanner from. any Ideas of where I can rent a scanner? Im in central florida, kissimmee area.

 

The scanner wont help unless theres a code. I really sounds like the ignition switch. it only around $20.00 but its on the top of the steering colume. i wish i could find the site that gives you a step by step on how to do it. I had the same problem.

found it: http://shbox.com/ignsw/ign_switch_repl.html