I replaced the opti spark, coil. Icm and MAF, Will start ride drive but when parked will not restart when warm. Test drive was around the block so no real heat issue. After cooling off and a regimen of hard starts it will finally fire. This is a 94 Z28 LT1. All help appreciated!

 

did you put the heat sink paste behind the ICM?

 

Yes.

 

Did you have this problem BEFORE you did the replacements listed above?

What brand Opti did you install?

Describe what exactly the starter and the engine do during what you describe as "a regimen of hard starts". Is there any indication that the engine may be flooding? Is there any indication of inadequate fuel flow?

 

Highlighting Fred's last note....did you check FP "when" this hard start engine warm issue occurs?

 

Been 95 degrees so for now we are trying to get the program and cable to
Injuneer's sticky to diagnose the prob. thanks for all the input.

The first prob was no spark and is what has lead to this point.

 

After replacing the Opti does the PCM need to be reset? My Mech has not been back for a week so looks like this may become a solo ride! Thanks to all!

 

No. If you wanted to clear them pull the PCM BAT fuse for 30 seconds. That way you will know if they come back. Won't keep it from starting if you don't.

 

I noticed an attempted theft of battery before this all became an issue. Seems the thief got scared, I rem going to the big box outlet and upon returning to my car it would not start!
The negative cable was loose like wobble less than hand tight and had to re-tighten before the car would start.. Would the arcing of the neg cable in transit cause harm to the Electrical sys? It did restart and make it to the drive it now so earnestly protects 24/7. For the question of why was the car not locked to prevent theft> It's a Vert you wanna Rambo Knife slot or just what they can steal? You keep nothing in the interior of a Vert!

 

I just went threw this exact same thing with my 94 z28 lt1.I had to put 2 optis on my car.The first one I bought was bad so I had to buy a second one.Do you have a way to check codes.Look for code 16,thats the opti.But that was my trouble with this problem.I did the same thing.ECM,coil,opti.Then a second opti.

 

If you want help, you have to respond to the people who are trying to help you. The only semblance of a response I see is something about "first prob was no spark". Are you saying that you had no spark, and then started replacing all those parts you list in an attempt to fix the problem? What diagnostic procedures led you to the conclusion those parts needed to be replaced?

 

I appreciate the responses that have been made on this thread That said I have not heard from my Mech since before the fourth. Brand names were not discussed prior to that. So I have no other info to share other than he had the scan tools to show no spark! Last communication was a new scanner was to be purchased instead of the Cable mentioned in the OB1 thread. I have been under the weather for 3 mons and would delve into this my self which may have to happen. Limited income means limited resources. So as you can see it's taxi for now! Thanks again to all that have responded. I will from refraining to post until it rides and drives!

 

Ok here it is hot off the press! I had waited until he returned to start the Z as it is his project! He put the key in, turned it and it started. He had purchased a new scanner plugged it in and no codes! After 20 starts and around the block several times he returned and it still no codes, rides and drives! The issue seems to be he used to much sea foam or start assist fluid down the throttle body when initial start was tried! Hopefully it's done deal and can move on to other issues with this fine automobile that was a piece crap in the recent past! . Just teasing I wouldn't trade it for anything! Thanks to all those that took interest in the Thread and offered advice!