93 FZJ80
Been having a terrible running issue for weeks. Super rich and barely stays running. OBD1 codes said TPS and IAT. Both tested out of spec so I replaced both, still had the same issue. Tested the wiring for them and it was okay.
Went back and looked at the wiring repair I did 5 years ago due to the EGR melting one of my fuel injector wires, found an additional wire that was half split. Although it didn't explain my issue. At this point had tested almost every sensor on the engine, checked timing, compression, the works.
Only thing it could be was wiring.
Pulled the engine harness and found the rear knock sensor plug was completely destroyed, and actually the plug itself fell completely off the wire with a mere bump

Ironically, it was the only sensor I didn't check because it was in an extremely difficult spot to check, and I assumed it wasn't it due to not having a code for it. Doh!
Since 90% of my connectors have broken locking tangs, going to try to source a new wiring harness altogether. Maybe even rebuild the head, 350,000 miles and pretty poor leak down results with the highest being cyl #3 at 40%
Although I've been well aware of my bad valve seals and burning oil, hard to miss the smoke LMAO.
I'm not mad. Bought the truck for $900 6 years ago and it's been my daily driver since, and I haven't had to do anything other than normal maintenance and a few parts here and there.
Don't know why the OBD1 codes didn't give it away properly. Thinking of doing an OBD2 conversion if possible
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