i just picked up an 87 camaro and when i'm doing 55-60 for more than 10 minutes, the check engine light comes on (either in drive or overdrive).

Then it goes away.

the car runs smooth and accelerates well, so it doesn't appear to be an obvious problem.

I'm completely new to camaros, having previously owned jeeps. any ideas?

 

Do a search on how to pull ECM trouble codes with a paper clip.
Or just take it to the nearest AutoZone, they'll pull the codes for you and tell you what's wrong.

Hope this helps.
Lou

 

Sounds to me like you have an EGR problem. I would first check for vaccum leaks after first checkin the computer codes. Just put a jumper between terminals A and B on the ALDL connector and turn the key to the on position and it will flash the SES light. For example the first code you will get is 12 which will be 1 flash then a pause then 2 flashes and it will repete 3 times before moving on to the next code.