Our Community is 940,000 Strong. Join Us.


Won't Read Computer


Prix87
07-11-2009, 11:16 AM
Have a 5spd 85 camaro with 2.8L mpfi. When driving car lost a little bit of performance and check engine light stayed on. Stalled when from a stop. Later tried to hook my scanner up and wouldn't flash any codes. Wouldn't start until I kept on the gas pedal. When finally got running it would hold a high idle. If i gave it gas it would putter/hesitate and then idle would increase. Any suggestions???

89TtopRS
07-29-2009, 12:15 PM
I have an 89 2.8MFI and I used a jumper wire on the ALDL by the pedals *just above the gas pedal*. Jumper the "A" to the "B" and turn the key to on but do not start the car. The check engine light with flash a codes.

One flash
pause

Two Flashes

That means the car is displaying the diagnostic code of 12. After about 3 times flashing that code the ECM will now display any faults. You can find the same process online. Also of you look up GM fault codes it will tell you what the problem(s) are.

I had a code of 34 for like ever and turned out to be the ground wire for the MAF sensor was attached to the damn alternator once I removed and attached it to the chassis ground the light cleared. Also make sure that you clear the code by removing the ground wire to the battery!
Good luck.

Prix87
07-29-2009, 01:39 PM
I've tried. I have obd1 scanner that worked on the car previously. Tried grounding the a and b ports but that didn't work either. Any suggestions? I've got to have some bum wiring somewhere.

Prix87
08-26-2009, 09:05 PM
Bum ecm ended up being the problem. Was reading the haynes manual about prom installation. Said something along the lines of.. after installing new (or old) prom, if the check engine light stays on when you start the car in diagnostic mode (A and B terminals grounded) that the prom was installed backwards or is faulty. So i swapped it out with a matching one from a boneyard and things be sweet.

Needless to say it will flashes code 12 now. :iceslolan

Add your comment to this topic!