The other day while going down the road, my car just shut off. It eventually started back up after several tries.

I hooked the laptop to it, and I had a code 16 lo res failure, and also a code 36 hi-res failure.

I cleared the codes and went for a ride. The car quit again. got a code 16 and 36. Cleared them, managed to get the car started, and made my way home.

Car quit in the driveway. Only got code 36 Hi-Res failure this time. It quit again. Its hard to start the damn thing. Code 36 is the only code I'm getting now.

The opti in this car was replaced 2 yrs ago with a complete AC Delco unit. I only have a few thousand miles on this opti.

Any possibility it could just be the opti harness?

 

PS - can the opti harness be removed without removing anything else?

 

Yes, its possible that the Opti harness connector is corroded or damaged. The harness can be replaced. It starts at the gray connector on the bracket on the passenger side of the intake (same bracket that holds the EVAP purge solenoid), and runs to the Opti. The factory part is very expensive. Casper makes a replacement harness for about 1/3 of factory cost. If you want a factory part, Shoebox has the part # on his website. Make sure you get the harness for the non-vented Opti, because the connector is different on the vented Opti.

http://shbox.com/1/evap_sol.jpg

 

Thanks Fred! I'm checking the cable out today. I'll probably order a new one from Caspers tomorrow.

 

Checked the harness. It looks like new, and I used the multi meter to check continuity and it was good on all the leads.

I guess I'm due for a new optispark again

 

Isn't it the high resolution failure that shuts the engine down when it reaches operating temperature? As soon as the temperature drops, it will run again. This could be your problem.

Warren

 

It definitley shuts down after the engine gets good and hot. never does it when its cold and still warming up.

 

Its loss of low resolution (DTC 16) that shuts the engine down. With DTC 36, the engine should continue to run, with slightly less spart timing accuracy. Sounds like the optical module may be overheating.

 

I only get DTC 36 right now, but I have gotten a DTC 16 a few times last week when all this started. I cleared those codes, and just the DTC 36 comes back now, and eventually my motor quits running. Even if I'm just idling in the garage, just a DTC 36 will eventually kill the engine. Restarting it takes several tries before it fires off again.

I'm at peace now with having to buy another opti anyways, so either way its getting fixed.

Thanks for the help Fred!

 

I also got Code 36...Car started bogging, and shutting off randomly...Then usually immediately would start back up...

It was quite scary one time as I was at a busy intersection coming out the stop sign, when the car bogged and shut off with cars coming my way from BOTH directions...I immedietly started the car back up and it bogged a bt then puttered on its way, then went back completely to normal...Not even a SES light...Scary stuff man, Im going with a AC Delco opti from shoebox's provider, pretty nice deal

 

i had the same issue with my 94 twice, so i swapped it the vented opti setup never had that issue again. If you have the time i would do the 95+ opti swap.