Back Firing

[Master]

During my 2nd run of the day my car started back-firing when idling or running at lower speeds. I thought possibly the float levels could be too high or a vacuum leak? Any thoughts?


Scott
4279454
SA 428
3:54

[ralphscott]

Scott I tried to send this earlier but got bounced so here it goes again. My guess is either fouled plugs or vacuum leak. The start up setting on the fuel air mixture is 1 1/2 turns on the mixture screws one on each side of the holley and you adjust from there. Flooding the engine on start-up will also foul the plugs. As for the vacuum if you have a vacuum meter and a plug in your intake for it you can easily check it. Vacuum is also dependent on the cam you are running, as a reference point, and only that I have a fairly radical cam and pull 10 inches of vacuum at 800 RPM. Hope this helps.

Ralph

[Brent]

Through the exhaust or through the carb?

Through carb = timing slow, check dist. hold down and see if it is loose,put a timing light on it.

Through exhaust too much timing, valve issue, fouled plug.

Good luck!


Brent
427 SC Chassis #4279401
Candy Apple Red/White
402 FE/Toploader/3.54