I have a 94z28 with a no start condition, so I have been going through the troubleshooting charts. I removed the harness from the opti and the connector was cracked, so I checked ebay to buy a new one. My opti uses the harness with the long flat connector which is shown to be 1995-1997, the earlier ones look different than what I have. So either someone converted to the later opti or the engine has been changed. Any way I can check to see what exactly has been changed? FWIW it looks like my optical sensor is dead so I will need another opti, good thing I didnt buy one ahead of time for the 94.

 

do you have any pics of the connectors? might help id things.

 

I got this picture from ebay, the long flat connector is what my opti uses which is described as a 95-97 style. When I looked up the 93-94 style they showed a more common looking connector similar to the ones seen on the engine on different snesors.

 

someone swapped out the opti or maybe even the hole engine at one time, a 94 should have the other style.

 

http://shbox.com/1/block_vin.jpg check to see if your cars vin matches blocks vin

 

Thats what I figured. I am going to get the opti off to confirm, but is there a casting date somewhere easy to see so I can check the block date? Any differences between 94-95 engines other than the opti and related parts up front?

Thanks for the pic, I will check the vin.

 

one more thing to check out when the opti is removed is the cam dowel and the backside of the opti.

 

the engine would have to have a diffrent cam in there other than a stock 94 cam as well, since the 94 cam dont have the hole in the center to line the opti up.

 

Just pulled the opti, definately a later 95 up vented unit with the corresponding timing cover and cam. The opti is supposed to be only 6 months old, but following the diagnostics I have found here show a bad optical sensor. The water pump shows rust stains all around the bearing, looks like it may have leaked and killed the opti. I removed the cap and did find some moisture, other than that it looked new. What size torx bolts hold on the rotor? I didnt have one small enough to remove it, I want to pull the cover and look at the optical sensor. Any way to test it, maybe with a diode test setting on a DVM?