And that is the main reason that I always recommend having a diagnosis done by a dealer prior to throwing parts at a car. Paying them $1-200 for a diagnosis will ultimately save you a lot of money over an internet diagnosis and replacing of multiple good parts.

Now they aren't ecstatic when you pay for the diagnosis and go "Thank you for that but the $x for the repair you quote doesn't fit my budget this month. I will bring it back after payday."

But it does work.

Perry

 

Did replacing the ECM fix your problem? I was able to finally install the optispark today, and so far the car is running great. Hopefully, this takes care of the issue! I should know for sure after driving it this week.

Thx again to everyone for their help

 

Congrats on yours. Replacing ECM didn't fix my problem. Still working on it. Let me know if any problems after you drive for awhile.

 

Sadly enough my advice to have a Dealer diagnose the problem only works if you have a competent and honest dealer. I do believe most but not all are competent and honest.

I did run into a situation in Las Vegas with a dealer near my work, that I went to to diagnose a VSS problem on my 93 Camaro. I knew that there were 5 things that could cause that problem, VSS speed sensor, PCM, and 3 others. Not wanting (I didn't have a lift at the time) to do the diagnosis myself I decided to pay the dealer to do it. Dropped the car off and came back after work and was told that the fix would be a bit over $3000. They had diagnosed all 5 possible causes as all being bad. I gave them my $ sob story and took the car home and put in my spare pcm. No change. I also had spare parts for 3 of the other 5 potential causes....no change. So I labored to clean out the garage of several cars and got the car up on jack stands and pulled the VSS sensor. I was about to put a spare in when I realized that the plastic gear that drives the VSS sensor had slid forward on the tranny output shaft and wasn't driving the VSS gear. Put a pry bar in there and relocated the shaft mounted gear and voila all was working and it is still working 10 years later.

That dealer declared bankruptcy about 6 months later nationally (had lots of stealerships).

I feel for you. When a dealer says it is the pcm, and you replace it, it should damn well have been the pcm. That is why we go to a professional to get a professional analysis and recommendation.

 

Thx, drove it again today with no issues. I'm still afraid to drive very far until I have a few more short trips under the belt.

So, did the dealership give you any other advice? If the optispark, ECM, ICM, and Coil are good, I'd double check all the connections for each of those pieces(it's free). If that's not the problem, maybe it's a fuel related issue.

I did a lot of reading on forums before I replaced my opti. Many forums I came across, people said their optispark didn't work out of the box and had to get another, maybe you got a bad one(just a guess). I saw this video and it convinced me to replace my opti, maybe it will help you.


I wish you the best!

 

Thanks for the advice!!

 

I just wanted to give everyone an update. I have been driving the vette all week and haven't had any issues. Looks like my problem was definitely the optispark. I hope this forum can help others in the future.

 

I never would of guessed glad you got it sorted.

 

I was in denial, didn't want to believe it was the optispark. I learned a lot and know what to look for if it fails again. Thanks for your advice, I never should of doubted you!

 

Just wanted to give a final comment to possibly help someone with the same problem. Even though we had identical problem and the solution for yours was to change the opti, the cause for the problem with my car turned out to be a bad memcal. The memcal was replaced and car now runs just like it used to. It was very frustrating but thank God it's fixed.

 

Great News, glad you got it fixed...it's a great feeling ! Forgive my ignorance, but what is a memcal?

So I did a postmortem on the optispark, and believe I figured out why it failed. The optispark rattled and when I removed the cap, I found a screw that secured the rotor came loose (can be seen in image below). Does anyone know if this is a common occurrence?

 

I have read about it happening before to some forum members, I used there suggested advice and used some blue Loctite.

 

Yes it is a great feeling to finally have it fixed. The memcal is the chip that runs the ECM. From '94 on they called it a prom.