Symptoms are:
-codes 16, 36, 41 and 42
-car starts missing once the car warms up

Other Info:
-1995 Z28 M6
-fresh rebuild with LE2
-Using MSD coil (new), Standard ICM (new), thepartsladi Opti (new, but one of the last ones before she went AWOL), GM opti harness (new), MSD wires (new), autolite spark plugs (new)

Terminal A and D on the ICM driver connector both read 10-11 with ignition on.

Terminal B on the ICM driver connector read 2.1 - 2.6 while cranking.

I took a test light to terminal C on the opti harness with the ignition on, but not running and I got no light. I did however get one on terminal D.

Measuring the opti harness
-A = 5
-B = 5
-C = 11
-D = 0

Coil continuity test (MSD coil) - 4.87 ohms on each terminal

Thoughts?

 

When you clear the codes, how quickly do they return, particularly the DTC 16 and DTC 36 for the Opti?

 

Well I started my datamaster recording and 36 was the only one showing. I believe this was right after a reset, although not 100%.

5 seconds after start up 42 kicked in.

I drove around the block, varying RPMs from about 800-2k.

Looks like it kicked into closed loop at the 170 second mark.

At the 180 second mark, the car died and tripped 16, 41 and 51.

 

Optispark 100%. When ever i replace an opti with code 36 or 16 it fixes the problem. Check the voltage that the ignition coil produces if you want too. but even when they are producing lower that good voltage they dont set off codes.

 

That's why I asked about DTC 16. That's the code for the Opti cam position sensor low resolution pulse signal, and when the signal fails the PCM shuts down the fuel system and the engine stalls. Sometimes you'll see that as a stored code, but its infrequent. Engine stalls and DTC 16 sets, the Opti is prime suspect. But check the short Opti harness connectors on both ends for damaged or corroded pins.

 

Hmm, wont spark at all now. Hope I didnt ruin the connectors by doing these tests.

Is the short opti harness the one that leads from the top of the opti up to wiring harness by by the fuel rail? Or was "short" describing the connectors?

 

Yes. Starts at the grey 4-pin connector on the EVAP purge solenoid bracket on the passenger side of the intake manifold, and connects to the Opti.

The voltage on the signal wires (A & B) should switch between 0 and 5V as you slowly rotate the Opti.

 

Well that sucks, I thought I did the right thing by getting thepartsladi opti which was the hot ticket at the time. I bet I got someone elses return right before she vanished. Maybe if I contact Delphi they will refund my money. Probably not, but worth a shot.

Ordered a GM one from Summit, a new opti harness and a new pigtail for the ICM. I really hope this does the trick, because I am so hungry to drive this car after the heads/cam swap.

Thanks for the help.

 

Replaced Delphi opti with AC Deloc and codes are gone.