I'm having an on-going ignition problem, or rather the lack of, that is causing a lot of frustration with my 93. Weak fire at the coil and plugs. I put a new ICM last sunday. It cranked, and I ran it for 3-4 minutes. It was running rough, but I blew it off to cold weather, and the fact that it's been sitting since before Christmas. I sometimes "positive think" my way to disaster! Been hangin round those salesmen too long I suppose.
I had taken the old ICM to 3 differst auto parts. Auto Zone, NAPA, and Advance. Advance tried to check it, but couldn't the others all suggest the GM dealer, who wanted a gouging $60. So I took the risk, just bought one. ($80, AutoZone). Finally I called the local O'Riley's yesterday. Just for the heck of it I carried the old ICM, the original unit I took off last Sunday. It was good. So I guess I have a spare. Don't know it AutoZone will take it back, since I used the grease pack. I bought a coil yesterday. Ittried to crank. But won't. This car has always cracked right up. With only one bump of the started, regardless of how cold it is.
I'm stumped as to where to go next. In way of history. I put a new Opti distributor, and plug wires less then 1000 miles ago. I rechecked all the electrical connections as best I can. I'm getting No Codes. 12-12-12. 12-12-12.
It shouldn't hurt to crank it with the rubber breather removed? The unit that goes between the air intake, and the fuel injector unit on the top, front of the engine? I believe this is the throttle body.
Any ideas on where to go,appreciated.

 

If it mis-fires with the rubber breather removed, the spark will go to the front of the car and might catch something on fire (radiator shroud)? Just make sure you have an extinguisher and don't drive it that way. I don't see the advantage of removing the aircleaner & rubber bridge.

How many miles on this car? My '93 had 90,000 mi and the only troubles I had were the opti( the new one from GM--I never should have switched out the old one, it was fine) and the ICM.

You could have a bad crank sensor. Just had that go on my F-body at 133k mi. Or bad coil.

I would suggest, if you have the know-how, buying a scanner and whatever other electrical equipment you need to trace this down, or else take it to a reputable shop and make them do it.

 

What do you have the dwell set at?

 

 

Dwell is like vacuume advance, right? I didn't know there was such an adjustment with the opti. Sorry to be so ignorant. Maybe you can enlighten me.

 

have you checked for a bad ground

 

You replaced the ICM and have weak output at the coil indicates the coil is defective. You can test the coil by disconnecting the primary and putting a .05 to .1 MFd capacitor across the primary (you can use a capacitor from an old points type distributor) and pulsing the primary with 12v and see if the output wire will jump at least 1/2 inch and have a ,"snappy", spark.