I have a 1987 IROC tpi that will start up fine cold but if I let it run for even 3 minutes turn it off . Try to start it up agin it will turn over fine , but it will not start . If it sits for about five minutes It will fire right up again . Even if the motor is hot after driving . It wont start if I turn it off ,and try to start it up again ,let it sit for a couple of minutes it fires up no prpblem. The motor is not stock ,it is a383 stroker , trick flow heads , accell 24 lb injectors, adj afpr ,slp cam ,accell igntion custom chip . The car has just started to do this . Sorry for the huge post .Any help whould be great . Thank you .