I have just completed an engine swap into my 86 BroncoII. The donnor 4.0L engine came from an 93 Explorer with auto trans. My B2 is a manual so I needed to convert the engine (flywheel, pressure plate, etc) to a manual. I was told that I also needed a PCM for a manual 93 Explorer, and purchased it.

However, the engine ran but very roughly. I checked the codes and it stated that the MAP voltage was low. I checked the wiring from the MAP to the PCM and found that the wires did not go to the pin locations on the PMC as stated in the electrical manual. (there are other wires not in the locations listed in the electrical manual)

Can't understand why? The engine ran with the auto PCM with wires in the different location from the electrical manual, but not with the manual trans PCM. Should I change the pin locations to the locations listed in the electrical manual?

 

Howdy and welcome to FTE.
Seems your post wound up in the 3.8/4.2 Forum, instead of the 4.0 V6 Forum.
I'll move it there and maybe you can get some good help.

Again, welcome to FTE and hope you enjoy it!

 

Hope you guys can help. A mighty strange situation. It is not necesserly a 4.0L issue. Could be on any vehicle.

 

I was thinking that Ford may have had a special run of the PCM from a different supplier that had different pin-outs and then used the appropriate wiring harness. This could account for the strange wiring/pin locations.

 

Got it fixed. Changed some of the pin location for the PMC to match the electrical manual. I still can't figure out why it was different.