I am not getting fire it seems. I took a spark plug wire off this evening and held it to a grounded non-car metal source, no spark when trying to crank. I checked fuel pressure and it is holding at 40-44psi (new pump) w/ key on. I wiggled a few wires and still nothing. How do I nail down the problem? I should mention I have a new MSD Blaster coil and new Taylor wires. It has been really wet around here with all the rain so did it kill my opti? How do I test optispark distributor? I have an electrical tester with the light to tell if getting power. Should I remove all my MSD 6A w/ GM adapter harness stuff and rule that out?
The project and related items of interest: 1993 Z28 LT1 A4 new fuel pump, fuel filter, MSD coil, Taylor plug wires, MSD 6A with GM adapter harness.
Thanks for any help or advice!!

 

Don't quite understand what you did...

Are you saying that you held your plug wire up to a wrench or some other metal object looking for it to just jump to it? If thats the case, you need to go to something that is a chassis ground to complete the circuit.

If you indeed don't have any spark at all, I would first remove the MSD from the system and try again. Need to get it down to the lowest common denominator and work from there. if it fires without it, hook it BACK into the system to verify that it is the problem. If you still don't get spark WITHOUT it, then you can move on to testing the coil and ignition module. Once those are ruled out, then you can pretty much blame the Opti. I always check those things first though, cause they are easy to get to and easy to check..

Good luck!

Dave C.

 

My ignition module is the stock one and has 100k+ miles on it. Should I just go ahead and replace it for good measure? a cheap insurance..what do they cost$ ?
I will check the spark out like you suggested. The car ran a few miles this morning then just died while at 55mph on the highway.

 

You can replace it if you want, but to be honest, if it works then why bother. It's all solid state, and either works or doesn't. I would just backprobe it and see if I get the right numbers. If you don't already have a haynes manual, go get one and follow their troubleshooting process.

If the car just up and died at speed, I would suspect the coil though. Opti's can do that too, as can modules, but it's more common (as far as I'VE seen) for a coil to up and completely die like that. Be sure to check the MSD as well. I had my MSD-6AL croak on my one time, so it definately CAN happen..

Dave C.

 

The coil is 2 months old. I hope that wasnt it. I have a Chilton's book is all. I'll check their troubleshooting procedures.

 

I disconnected the MSD 6A and wiring harness. still not running. It sometimes will start for 1-2 minutes, then shut off. Mostly when I let it sit for a while, then try and it might start. Will not run for more than 2 min. though. Just cuts off suddenly, no skipping or spuddering. Fuel pressure good. I ordered a new IgntnContrlModule so it will be here tomorrow and I'll try it. The MSD Blaster coil or Opti seems to be problem if not ICM I would think. I may have an extra coil and I'll try it. What else could anyone think of? What does a bad opti do? I thought with a bad opti it might run funny before it cuts off. ??? Help!?

 

would a bad idle air control module (the sensor/plug under the throttle body on passengers side) make my car not start up?

 

No. Thats the Idle Air Control VALVE. It's kind of like a huge needle/seat deal, and controls the amount of air entering the engine at idle. The body of it is a stepper motor controlled by the computer. If it idles at all its working (although I would wager it needs cleaning - and the ONLY thing I've ever found that works well to clean it up with is acetone; You can just swipe some from your wife/girlfriend - it's finger nail polish remover! :P ).

I think your on the right track with the stuff your doing now. Just be sure to get out that manual and check the values of the ignition items. Oh, and be sure to check the stupid stuff too, like your ground strap. Bad grounds can cause all sorts of wierd stuff to happen.

Good luck with it..

Dave C.

 

I had Advance Auto parts order me a new Ignition Control Module this weekend and I just mounted and attached it. My 93 Z cranked and ran fine. I am gonna go get it from the gated parking lot it's in and drive it home tomorrow(hopefully) all the way home if the ICModule was the problem. I had been going about 100 yds and it cuts off suddenly. I put the new ICM module on a little while ago and it idled fine for 15-20 mins. I put it in gear and drove around the parking lot and it did OK. Is it gonna put more of a strain on it when I get on the open road that might cause a failure from something else or does it receive the same voltage all the time to the ICM? My old ICM had 159,000 original miles on it. I called the guy I got the car from (orig. owner) and he never had it changed before.

Also I am debating on removing my MSD 6A. I removed the MSD Blaster coil this morning and put a new coil on but did not fix it. Could the 6A box have strained it and been the death of my ICM?
THANKS!