Engine Missfire in my 65.
Hey guys, I'm experiencing what seems to be an random misfire. It occurs during part throttle acceleration and while holding the throttle at certain RPM's.
Example: holding it in first gear part throttle at 3500 rpm's the engine suddenly bucks or jerks. I've noticed it's generally during high engine vacuum situations i.e. 13-15 hg.
Engine = 283 with Powerglide, Pertronix kit and a rebuilt Carter 4 bbl.
What I've done = Replaced the fuel pump and the ignition coil to no avail.
The most vacuum I can get at idle is 13 hg.
I have not checked the cap, plugs or wires.
The car starts, runs, shifts fine and under full throttle zero vacuum it doesn't miss a beat.
Is it possible that this may be a lean misfire, or too much timing? I do have the vacuum advance hooked to manifold not the "timed" port.
1965 Impala ss 283
Ermine White / Red interior
1970 Chevelle ss L78
Black Cherry / White Stripes
Last edited by sam65; 09-07-2014 at 09:22 PM.