It's been a long time since I posted here, the Z has been running so well lately that I haven't needed to post, well that changed this morning! I was on my way to work and all of a sudden RPM's drop to zero, then go back up then drop back down, it does this for about 5 seconds before completely dying. Could not get it to restart so I called for a tow. I got the car back to my house and just for the heck of it, I tried to crank it and it fired right up. I went to get my laptop to get the scanner hooked up and while I'm connecting everything it does the exact same thing and dies again (it ran for about 5 minutes). I checked the codes and this is what I saw:

Code 16 - Optispark low res pulse not found
Code 36 - Optispark high res signal faulty
Code 42 - Ignition control circuit, short or grounded

So I get everything connected and again it will not restart. I let the car sit for about 15 minutes, pull the PCM BAT fuse, and it refires once again. I started scanning, let the car run for about 30 minutes with no problems. Nothing unusual seen in the log file either.

I am thinking Optispark given the codes, I replaced my first one at 90k with a new OEM AC Delco unit and the car now has 124k on it. My first Optispark did not act like this though, once it died I could never restart the car. Also, battery voltage was at 12.5V with engine not running and at 13.5-13.6V with car running which seems a little low to me, could it just be that I need a new battery (it has been in for about 4 yrs now). Any help at all would be greatly appreciated!

VTHokieZ28

 

It may be the actual opti harness. I would check the connector for damage or corrosion.

 

Replace the Opti harness as 2000GTP stated. It is most likely worn-out after all this time. Plus if you have to replace the opti, at least it is new. Also check your grounds on/near the ignition control module

 

Agree'd i had this problem about 200 miles after my old opti failed and i had just put on a new one, i was angry as one could imagine (thinking imediately another opti and all my work wasted), i began checking the car over and found with a slight wiggle or jar of the harness it would work fine, faulty even though it visually had no flaws in it. GM wants a hefty price of damn near $150 for the harness, this link provided is a genuine GM pigtail setup and pre-wired for less than 1/3 the price, i bought one, plugged it right in and have had no troubles since. Even if this does not fix the problem, at 125k, its probably a good idea anyway

http://www.eficonnection.com/eficonn..._pigtails.aspx

good luck!

 

this is exaclty what my car is doing right now. Same codes and everything. It's the Opti, This same very thing happened to my last Opti.Car would heat it, die, then let it cool for 10min and it would restart and drive for couple min before dieing again. I thought it was the harness at first, did all the tests in a GM Tech manual on the harness and actual opti which made it lead to the Opti..I bought a used one from a friend and replaced the opti and the problem went away for 8 months, now all the sudden this opti is doing the same thing

Im looking into a MSD unit right now

How come they dont have 93-94 Opti Harnesses in that link??^^

 

check coil wires they tend tto corrode try to wiggle it while turning it over.

 

Does my camaro have an opti system in it? 1996 Z28...

 

Yes all LT1 engines have an Optispark....Its the distributor

 

Cool, I thought they changed something in the opti from likle 94 to 95 or 96. My friend got his wet when power washing his car and he said I didnt have the same system so not to worry as much about water getting in like his...

 

They did, the 93-94 years had the non-vented optispark, the later years had the vented optispark. Vented or not, I would still worry about power washing the engine bay.

 

I made that mistake back in the day when I was new to the LT1s......I hate even driving in the rain now

 

That sucks for sure. I hate driving in the snow! lol Snow flies Im parked!

Thanks for the info on the opti, much appreciated!