I recently changed the water pump on my 96 z28, it leaked from shaft seal, after the change and a new themo, I sped all over town that night running fine as ever. Next morning went to Dr apt, car was sluggish no power trans shifted real quick or not at all it was just crazy . So we hooked it up a scanner and it give a low voltage code on the tps, did a few scans shut it off, cleared the codes, took a shower got in it and it would start, turn over fine, but no start. Check fuses , PCM fuse blown well the one under the hood, the 4 wires going to the distbutor had burn off one to two inches of insulation, no voltage to fuse at crank (inside), replced coil module tried a different crank positioner, and the 4 wire harness still no start, is it time to buy PCM or what help me fellows, Jrshotrod

 

check all around the water pump for any pinched wires, wires between water pump and block, follow your opti harness up on passenger side and look for any sign of damage. do same on driver side follow wires from opti threw the coil and ignition coil module. look for any signs of a short with hot wire or ground. I'm thinking you fried the opti but could be computer like you said

 

Don't waste your time on the CPS as in your particular car it does not affect how the engine runs or starts. Most likely the opti is done for or something got shorted out during the pump replacement..

 

That's not good sign. Whatever caused the wire melt down may have also toasted the opti.
Or, the opti may have shorted out first from getting wet, and fried the wires.

 

If the red wire in the distributor cable is burnt (or pin C, if not red), then the distributor has shorted it's power input. The pcm couldn't deliver more than the 12v the distributor normally gets from it in order to damage it. The real question is could the pcm be also damaged by carrying too much current. My guess is not since the fuse protected it. What current rating is that fuse?

 

thks all of you with the help and it was the opti fuzzed out I went to ebay got an MSD and it fired right up and it runs fine with the other issues I didn't post cause I already remendy those problems but no one could have a bad streek of luck like I did, first it overheated, lost the key had to crack the VATS system, then the no start. Lots of new part complete i