91 ECU in 92 R/T

[LowSL2]

I got a 91 ECU from 89daytonashelby (thanks!) so I re-wired the 92 ECU connector according to the instructions in this thread:
91' R/T Trimcal in 92' IROC R/T

Once I got the engine started (took 10 minutes to get it to fire which could be because it sat for almost a month), I got a code 41.

The FSM says: Alternator Field not switching properly. An open or shorted condition detected in the alternator field control circuit.

I moved the wire from pin 57 to pin 8 like the instructions say. I even checked for continuity between pin 57 and the dark green/orange wire on the ASD relay which checked out ok. I dont have a 91 FSM yet to compare schematics so I'm relying solely on the schematics posted in the thread posted above.

The alternator is charging fine. I get 13.8V charge system goal and 13.7V at the battery. I just get this code 41. I have a powertrain diagnostics manual but it's for a 93. So it's no help.

Any ideas?

[lotashelbys]

I got code 41 when I put a 91 SBEC in my 93 to test it. Everything seemed fine but it just threw that code


BTW: I have both 91 and 92 FSM sets about 5 feet from where I am typing,maybe I will look at them here in a few.

[LowSL2]

When you tried it, did you move pin 57 to pin 8? If you do look at the FSMs, can you trace pin 8 on the 91 ECU connector? I need to know if it goes to the ASD relay or not.

If I got a 91 wiring harness do you think this would help things?

[LowSL2]

Ever since I put this 91 ECU in, the car drives weird at constant speeds. It's hard to explain. It's almost like a slight shudder or bucking feeling. It's really slight. Enough to piss me off and to make my passengers sick. At wide open it hauls balls though.