Hi all,
I am having trouble with my ignition timing I think, but it could be carburation. It backfires at high RPM when the secondarys open up and it kicks down for drive to L2.
Is the timing to retarded? That is my first guess. Second would be that the carb might be to lean in the primarys. I took it to someone to get it to pass emissions and he changed the timing to about 7 degrees btdc, and jetted it down....ALOT!
I have bumped the timing up to 10 degrees, but it still does it. Should I just time it for highest idle and back it off a few degrees.
Engine is a 350 rebuilt out of a 92' that has been heavily modified, but I have no clue what is inside or if the cam has been degreed.
Carburator is a Holley Truck Avenger 670.
Ignition is standard '78 HEI
Trans is TH350
Any clues as to what is causing this?