have an 1988 900 16 valve non-turbo ECU # 0 280 000 564. the
car will not go off idle with out going into over run cut off (
inj shut down then on like over rev). I have tried a new air meter
and all voltages were measured at the computer. All inputs tps,
air meter, temp rpm and power and grounds look and test good with
lab scope. I'm thinking computer failed and is not seeing off idle
or air meter input, but I can't prove it. I don't want to guess
since this is an expensive part. Any input would be helpful Thanks
Unfortunately this is what we have to do. Guess that is...
well, an educated guess we hope. This is why this site emphasis
learning the theory of operation. If your car was in my shop I would
first try an ECU. I have seen the ECU cause this problem before,
but we never know for sure untill we try a know good part.