stall

Hello i new i hope this is in the right place because i looked everywhere and cant find an answer. This spring i bought a 98 gmc jimmy form and old lady that overheated and blew head gaskets (low compression in 4 cylinders); so i pulled the heads sent them to machine shop to be checked and make...

It spits and sputters and backfires and the rpms drop until it kills. If you feather the gas you can get it to go for the most part, but the hotter it get through the day the worse it gets. It always starts up just fine even right after it kills you just can't get it to go once it's been driven...