dakleenupman

Following as I am also having trouble starting with same symptoms as far as I can tell.

hockeyhead019

curious to see where this one goes. sounds like you have voltage to fire the plugs and open the injectors. I would definitely look for one of those two to be fouled after all the testing.

qwiketz

I sent my dynaspark opti unit back to get tested and possibly rebuilt. Once that arrives back, I'm going to toss in some fresh plugs and gas and try it again. At that point, I'll have a freshly rebuilt ecu, working opti, new icm, and new plugs. If it won't start then I'll probably disconnect the ignition box.

ruby1993red

When you get this resolved please post how you fixed it.

qwiketz

Hi guys. Bob put a new optical sensor in the unit and sent it back. I installed the unit and almost got the car back together.

I tried to start the car today and it fired. It backfired a little out of the intake so I have some checking to do. Car fired right up but there's a misfire and I could see it proofing air out of the throttle body. It backfired good one time and put out the spark. Maybe a crossed spark plug or who knows... I'll have to research it. Any ideas?

I ended up putting new plugs. I completely drained all gas and replaced it with fresh fuel. I have the rebuilt dynaspark, new ignition control module. I double checked the chip program to my file. I also had the ecu solder joints redone which is a very common problem with the 92-93's.

T

Kevova

Do you still Crane box hooked up?

qwiketz

Still have it hooked up. Haven't had too much reason to disconnect it since I'm making progress. Car fired right up but is off a little on what sounds like 1 or 2 cylinders.

I don't know much about this stuff but if it's sparking when the intake valve is open causing backfires through the intake, I would think that something is out of order (wires crossed). I'll have time to check it out late tonight.

I thought I was careful putting them on but you never know.

Tom400CFI

Sounds like a couple wires crossed to me.

qwiketz

Hopefully that is the case. The car sounds like it's close- just a bit off.

qwiketz

Tom, you are the lucky guesser! 1/3 were crossed. Sounds mean as hell now!

Tom400CFI

You were already thinking about it...I just wanted to offer the encouragement to check the wires. Nice work.

LAGATTU

Hi guys ,
To be just in same case ,my 93 C 4 ,does not starts after opti Petris ,ICM ,coil ,Ecm (repaired by SIA,) renewals ,and for codes I get C 12 ,H 16....that's all ...My new coil have 12 v in ,but no voltage out through ICM A and D .no volts .With opti harness ,everything ok ,do you think ,that I have to renewed again ICM and coil .thanks in advance .

Kevova

You should have started your own thread. Do you have factory service manuals? The 16 is low resolution signal fault. What is voltage a terminal A of opti jumper on ecm side?

LAGATTU

Sorry for not having open a new thread ,,I am a young man with your forum .Yes I have FSM ,but you can read ,so many reasons for not starting ,that I get lost ......On opti harness, on A , I got ,4,71 v,,( 5 v is normal ) ,B 4.71 v ,C 11.84 v , D 0 .53 ohm .If these can , help .
.

Kevova

If you follow the dtc 16 chart if there is 4-6 volts on term A at connector for opti. Optispark or something with jumper connector. Have you cleared the codes? Did the 16 return? Did you replace all these parts because car would not start?

The manual should take you to the solution on your car. There are some more common areas that cause no starts. However you should not assume that's what will fix your car. Follow your manual and ask questions when you get stuck.

LAGATTU

Due to one engine stop on road and not any possibilty to start engine ,I replace all these parts to be ok for using my Corvette .After these parts replaced ,I have stared engine many times ,(without wa

LAGATTU

Due to one engine stop on road and not any possibilty to start engine ,I replace all these parts to be ok for using my Corvette .After these parts replaced ,I have started engine many times ,(without watert pump ,before reassembling all ) .After everything in place engine started after few seconds ,as usual ,and then I have checked ,if cooling fan was starting ,ok ,rpm iddle 450 rpm .everything ok ,and after 20 minutes ,engine was going erratic ,some cylinders ,not ok ,and then engine stop ,exactely the same way that it fail on the road .Since then not any starts ......and I am stuck ......Thank you if you have some ideas....
Yes I have cleared codes ,but H 16 or C 16 ,are coming back ......

Kevova

You need to follow the 16 chart. I would contact petris about the opti. Did you replace the jumper harness to the opti?

LAGATTU

Yes I replace opti harness,it was supplied by Petris.