I have a 89 camaro RS 305 tbi auto.
I noticed the check engien light came on a few weeks for no apparent reason as it was still driving fine.
So yesterday i took it too checkers too borrow there code scanner to check the code for whatever reason it said no codes where stored and the light was off. so i drove it around and what do you know it cam back on.
so i checked the code again and it still said no code. then i disconnected the battery for 5 min and reconnected it and drove around and it was still on

So the question is now what

 

If no codes are stored, you'll need to have it checked while the code is active and the light is still on (leave engine running etc). With hundreds of different possibilities, nobody can guess what might be wrong.

 

Pull codes manually. Maybe Checkers is trying to check with OBD2 or something. Grab a paperclip and read: https://www.thirdgen.org/service-eng...ht-error-codes

 

Mine did the same thing for the longest time. It popped three codes in two was vac and fuel related <once inspected codes where wrong. The third very strange was a code for Chry I think it was which stumped the mech. Mines 90 formula with tbi. Best bet is what guy above me said let it run till light comes on stick the grand oll coder key under the dash and count the flash's. Also I tore out all but straight pipe from headers back if youve done the same that is a high possiable for why.

 

Thanks
ill try the paper clip thing tommorow, however for whenever the check engien light was on i realized the speedometer cable was real loose and the thing was bouncing around and shaky
and today it stopped working so i am thinking thats it if not ill try other peoples suggestions