I picked up my 87 IROC 350 back in January and put about 2,300 miles on her. Today the light came on. I pulled over at auto zone to have them do a scan on the codes and they didnt have the old ADL style scanner. I had to purchase it instead. Before I opened it I started the car and the light was off. Is this a glitch? Should I scan it anyways or take the scanner back for a refund since its unopened?

You don't really need a code reader. but for now keep the code reader, but don't open it. You can return it later.

I'm going by memory...I have a scan tool so I've forgotten the manual way to read codes. Locate the ALDL. Ground the A and B terminals. Turn the ignition to ON (don't start the engine) and watch the SES light. It should blink a Code 12 three times, then blink what ever trouble codes are stored (again, three times).

Search the forum of look in the tech articles section. There should be a DIY procedure someplace here.

I'm willing to bet you had a Code 32 (EGR).

Edit I found a link that may help: http://www.automotiveforums.com/t679458.html

Thanks. I just found it odd that the light will turn itself off after you restart the car. Normally it should stay on until the issue is fixed or it went through several loops and is stored in the computer.

on OBD1 the codes are normally cleared on start up, then reset after the car goes into closed loop and the ECM finds a problem. unless it is a catastrofic fail then it goes into limp in mode if it can even run. however the fail codes are retainde for 50 starts then dropped.

Thanks for the replies guys.. I finally got around to checking the codes on the car by grounding the A & B terminals. The only thing I am seeing is the usual code 12. The car shows its fine. It would flash once, pause, then flash 2 times. I have not had anything done to the car since I last posted. I guess the code cleared and I need to wait till it comes back on to try again?