Join Date: Aug 1998
Location: Broomfield, CO, USA
If it's backfiring thru the carb, Is the ignition too advanced? My engine will do it every so often, usually under load or just before the trans downshifts. Single pop thru the throttle body, then it's fine. I have computer controlled ignition, so I will have to alter the timing map if it's wrong.
69 Malibu, supercharged fuel injected 454 big block, 700R4 trans, 3.55 posi 12 bolt rear
There's no replacement for displacement