...We'd have known that a week ago Monday, if you'd responded to B.C's question at the top of this thread. We are very lucky to have Chandrakumar on this thread. Iatrogenesis is quite prevalent here at times. I've had occasional bouts with it myself. Starting a new thread (240-1983) is an excellent idea.

I don't believe Oop is familiar with our common acronyms yet, so here are the two plugs that Chandrakumar mentioned:

TPS = Throttle Position Switch, 3 wires (for '83-'84 harness) are Orange, Black, White/Black (if White/BLUE, harness is '85)

IAC = Idle Air Control, 3 wires (for'83-'84) are Green/Red, Brown, White (White/BROWN for '85)

The harness lengths for these 2 plugs allow incorrect swapping, to the ECU's detriment. The IAC is harder to access than the TPS, so disconnect the TPS plug and check the wire colors under the rubber boot.

Even if they are correct now, the ECU damage could have been done earlier.
Let us know what you find—either here or in the new thread.

P.S. Maybe you can put the squeeze on whoever sold you the car as a 1985?


--
Bruce Young
'93 940-NA (current), 240s (one V8), 140s, 122s, since '63.