I need a little support on my 72 chevelle.
Whats the best way to track down a backfire thru the exhaust?
the motor is probably a 73-74 454 with a new holley 650 with a
hei ignition. I've adjusted the timing to spec, 10 btdc then advanced.
brand new accel 8mm wires, and a cap and rotor, the plugs looked fine.
I get a back fire during accelaration(either a loud bang or a mellow putt-putt). Even idling I can hear
a slight mis-fire. I've only had the car a year and don't much of its history.
I'm wondering if it might be my hei module, cross fire thru the aftermarket wires
or a coil gone haywire. Is there a checklist I might follow to find the problem
THANKS IN ADVANCE
RODNEY - '72 CHEVELLE CONVERTIBLE
454 -4SPEED MUNCIE WHITE W'BLACK STRIPES