Started. Won't start. OBD1 reader won't connect.

[vtraudt]

I went to the local junkyard and picked up a PCM module from the same car.
Plugged it this afternoon: same problem. The OBD1 reader comes back with "can't read data", no CEL when turning ignition on, no fuel pump priming.
So it is not the PCM (unless the one I picked from the junk yard has the same problems).

What wire connections should I check that are the most likely to 'disable' the PCM or preventing it from (for example) turning the fuel pump on?

With the PCM ruled out, I took the engine apart, removed UIM, all connectors, intake, battery, coil pack, ignition wires, power steering lines. Disconnected the wires to the alternator to be able to pull the fat PCM cable and cable duct on the backside of the engine up.

Opened the plastic duct up and pulled all wires out.
With everything exposed, plugged the PCM into the plug (now on top of the engine, grounded), and plugged the OBD1 code reader in and hooked up power.

Reader not reading. Wiggling and pulling the wires then after several tries turned the fans on (occurs at the beginning of the OBD1 test). Wiggling and bending narrowed down the area of the short. Once narrowed down, cut insulation, tape and flex duct off and found this at the wire of the DPFE (?) sensor wire/connector:

With the wires pulled apart, the CEL is now on, and the code reader connects to the PCM.

Now I need to insulated the wires (liquid tape and high temp tape) and put everything back together (which will be a big problem getting the wires all pressed together tight enough to fit again into the square duct), then installing and connecting.

Hopefully, this was it.

 

[turboman57]

Cool, I'm glad hear you are making progress, those wires gave me trouble too, on my 95, had to fix all three that came off that side of the fuel rail, IAC, IMRC solenoid and DPFE sensor, after that no more codes. Hope that fixes it for you. Seems to me this car has given you a lot of grief, many would have given up on it long ago.