Well it's been almost 2yrs with zero problems until yesterday.

Ran to gas station to fuel up (car off obviously) started it up and within 10 seconds it died. Cranked like a champ but nothing. So I had wife get in so I can push it out...she popped the clutch on me and it fired!!?? Took home 2 miles away backed it in and about the time I closed the door it died again and hasn't started back up since..

Ran codes. 41 and 42 came up reset turned key cranked some more to make sure those were the right codes since I did wiggle stuff at gas station..

Verified 41 and 42 are my only codes..

Both coil and icm were under lifetime warranty so I replaced them just because that's what happened to me back in 2011...

So I got that feeling I'm answering my own post but want to make sure I'm thinking clearly...

Opti dead....?

This is on a 1993 z28. With cai and hooker headers only..

Thanks art

 

If the optical cam position sensor in the Opti died, it would set DTC 16 and DTC 36. Only DTC 16 would prevent the engine from starting. The diagnostic charts for the 93 LT1 do indicate that DTC 42 will set if the signals for the high and low resolution pulse circuits from the Opti are shorted together. Check the short Opti harness for bare wires, damaged or corroded pins.

The diagnostic charts for both DTC 41 and 42 suggest that since the ICM gets its power from the coil 12V wiring, that the coil wiring should be checked.

I can fax you a .pdf copy of the diagnostic charts, but not until Tuesday.

 

That's cool

I did wiggle tests and even replaced both icm/coil for giggles

It's just weird cause its been months since I popped the hood...

 

I just metered everything and all wires are clean and no breaks still no spark

I even went after all the grounds too

 

And you had 12V at the coil and then at the ICM?

 

Lol when I checked voltage I had my hand on fuse box had volts take hand off ignition fuse must have pulled up... Pushed everything down car fired right up..


See Fred you made me think and I figured it out

Great job!