84 ECM problem??

[dhutch]

H-E-L-P needed from New Zealand! My 84 suddenly stopped idling, and the 'Check Engine' light stays on now. Car starts and runs fine, just runs real lumpy then dies with foot off gas. I connected A and B terminals on ALCL (engine off), and got no codes at all. Zip, not even a code 12, the Check Engine light just stays on. Another thing - the average mpg reading stopped working, rest of instrument cluster is fine. Any ideas? Is the ECM dead??

 

[vettenick]

Just out of curiosity, try disconnecting the TPS throttle position sensor. If the TPS is shorted, you'll lose the 5 volt reference and the ECM will "get confused".

 

[Magmotor]

On my '89 the Range, Trip OD, Averarge MPG & Instant MPG all read "0"...which = a bad ECM. The only fix was repair or replace so I replaced it. Fixed a lot of problems besides just those.