Does anyone have pics of where all the ground wires go to on a 1995 T/A motor and would having a ground wire going from the firewall to the bolt of the PCM case cause the PCM to fry?

 

Battery cable ground at RH engine mount bracket and RH shock tower lug.

PCM grounds at lug on RH side of block above starter and coil stud. Braided strap from coil stud to LH frame rail.

Grounding the PCM case should not need to be done, though it should not cause a problem.

 

Thanks for the feedback Shoebox. I'm at a complete loss for what is going here. Everything in my gut says it's the opti, but I have no proof that anything is wrong. No codes at all, even though the check engine light came just before the car let loose with several small backfires and then one large one, followed by immediate shut down. Engine turns over and almost starts, but never does and while trying to start it backfires through TB.

 

Sounds like rotor failure.

 

let me ask another question. As explained check engine light comes on, multiple backfires, and engine stops running, towed home and car sits for month and a half. Car has alarm system which kills battery. Had to charge battery today before checking for codes. I was relying on the codes to be there from when it happened, but if the battery died, then the PCM would NOT store them, correct? If that is correct, there is no way for me see codes unless the car is actually running and the PCM re-processes everything, right? Which would be a big problem since it won't start.

 

Codes are lost if the power is lost. Consider that codes can also result from other causes (ex. a MAP code because the engine died unexpectedly from another cause). Some opti codes can appear during cranking and some don't turn on the CEL. So, scan for codes, anyway.

 

Scanned for codes while cranking and got nothing. No codes were present before cranking. I'm assuming the optical cam sensor is still operational due to the almost starting while cranking and the small backfires through the TB. I would think if it was bad, these two things would not happen. As you stated, it does sound like the rotor. Seems to be activating, just not delivering it at the right time. If I'm getting any codes or communication issues with PCM I think I'm good there. Appreciate your feedback as always.