1989 mass airflow sensor
Thread Starter
Heel & Toe
Joined: Aug 2018
Posts: 19
Likes: 1
1989 mass airflow sensor
I continue to have an intermittent mass airflow sensor issue on my 89 Corvette. It latches the code 36 for the MAF burnoff, no other codes. Last night when I was driving the car, I started it and let it idle and then it just cuts out and wouldn't start. I disconnected the MAF sensor connector and reconnected it and boom it started right up. I did replace the ECM back in July since it was determined to be faulty by the local Chevy dealer (they diagnosed and I did the replacement work). Could this be an ECM issue? I haven't cleaned the connector with contact cleaner yet nor have I chased the input voltages for the normal MAF function or the burnoff.
Just don't know why I have to keep resetting it by disconnecting and reconnecting. But it ran perfectly after reconnecting.
Anyone have any insight they can share?
Thanks!
Rob
Just don't know why I have to keep resetting it by disconnecting and reconnecting. But it ran perfectly after reconnecting.
Anyone have any insight they can share?
Thanks!
Rob
Thread Starter
Heel & Toe
Joined: Aug 2018
Posts: 19
Likes: 1
So it turned out that the issue was another failed ECM, car progressively got worse and acted the same way that when the ECM failed. The rebuilt unit I got to replace it the first time was a Delphi rebuild, this time it is a cardone rebuild. I replaced it last night and just drove the car on a 100 mile round trip. Idle is good, throttle response is good, no stumbling or SES light presenting. One thing I did notice between the Delphi and the Cardone rebuild unit (77-6571) is that the row of pins for the PROM that is at the bottom of the unit was missing the far left pin on the Delphi unit compared to the cardone unit. I am not reinstalling the ECM officially as of yet as im still in test mode.
I hope this gives someone a good hint to chasing the ECM issue.
Some of the cues of a possible ECM failure:
1. Errant display information (ONE TO FOUR shift indicator stays on, instant fuel economy reads 99, always, intermittent SES light, no codes latched but SES light on, stumbling of the engine, SES light on and only reads 12 for diagnostic mode).....that computer does a lot more than I thought :-)
I hope this gives someone a good hint to chasing the ECM issue.
Some of the cues of a possible ECM failure:
1. Errant display information (ONE TO FOUR shift indicator stays on, instant fuel economy reads 99, always, intermittent SES light, no codes latched but SES light on, stumbling of the engine, SES light on and only reads 12 for diagnostic mode).....that computer does a lot more than I thought :-)
