I HAVE RECENTLY PURCHASED A 1988 IROC Z CAMARO WITH A 350 ENGINE. THE CAR HAS BEEN VERY WELL TAKEN CARE OF AND HAS ONLY ABOUT 55,000 MILES ON IT. THE CAR RUNS GREAT BUT OCCASIONALLY THE SERVICE ENGINE LIGHT WILL COME ON AND STAY ON. I HAVE HAD A TUNE UP, OIL CHANGE AND A DIAGNOSTIC DONE. THREE DIFFERRENT MECHANICS HAVE LOOKED AT IT AND CAN FIND NOTHING WRONG. WHAT DO YOU THINK COULD BE CAUSING IT?

THANKS!!!

 

you might want to check the codes the ECM will give u , it might direct you to the direction of the problem

 

dont bring you car back to those three mechanics......

 

If you just bought the car then I would suggest to purchase a good repair manual. Then if you don't know much about TPIs then learn all you can about it. Specially diagnostics and retrieving trouble codes from the ECM. Once you do that then you can make an educated guess on what could be wrong. It is easy to get ripped off by some mechanic who doesn't know how to interpret the information he is getting from the computer.
You will see that this stuff is not such big mistery. Anyway if you can get the code(s) and describe how the engine is running then it might be easier to diagnose the problem.

 

396,

Welcome aboard!

Let's see if we can't get some more data. If you have a GM OBD I ECM Diagnostic Trouble Code Retrieval Tool, you should be able to get most of the information you need. Most of us here at TGO call that a "paper clip", but some members have been known to stoop so low as to use a hairpin, or even a real piece of copper wire! Can you believe the nerve?

Anyway, take your paper clip, er, "Diagnostic Tool", a note pad, and your keys out to your car (unless you're already there on your laptop).

With the engine and ignition turned off, locate the ALDL connector under the dash, just to the right of the steering wheel in the driver's foot well area. There should be a small rectangular cover over the access hole in the lower dash trim.



Insert a tool as described above (paper clip) into the 'A' and 'B' terminals on the ALDL connector:



WITHOUT STARTING the engine, turn the ignition to the "RUN" position. Watch the Malfunction Indicator Lamp (MIL) and it will begin to flash. This is also commonly called the "Service Engine Soon" or "SES" lamp. The first code will flash three times, and will usually be a code '12'. This is encoded by one flash of the lamp, a brief pause, then two successive flashes of the lamp. Each code will repeat three times, so you should see a "Code 12" flash three times. Any other error codes will follow in numerical order, and each code should flash three times. After all codes have been displayed three times, the "Code 12" will again flash three times, then all other codes will follow as described earlier. This cycle will continue until the jumper is removed or the ignition is turned off.

After you have made a note of all error codes, turn off the ignition and remove the jumper immediately. If you forget to remove the jumper and attempt to start the engine with it in place, you could damage the ECM. For this reason you should remove it immediately.

Once you have a note of all error codes, report back with your findings or check this file for the decoding:

GM Error Codes.pdf.

You'll need Adobe Acrobat Reader to open/print the file.