Another 318 carb issue!!!

Ok, now another issue... Back at the carb again... I am leaning towards vacuum. It has the Edelbrock Performer .420 lift @ 204* duration. I cannot get this dang thing to idle!!! A list of check off and what I have done.

Reset the fuel mixture screws to about 1.5 turns. With the idle screw barely touching the plate on the carb (Edelbrock 1405) it idled at about 1800 RPMS. It would fluctuate from 2600 to 1200 RPMS. Plugged the carb for vacuum advance and checked timing (obviously idling way to high to check). Retarded it to bring the RPMS down. Got it to idle about 1200 RPMS (Fluctuate between 600 to 1800). At this point the idle screw is completely not even touching the plate.

Thinking I have a vacuum leak, I sprayed carb cleaner around the base of carb. Could'nt tell if fluctuation was from the spray or the fluctuation of idle. On side of caution I replaced the adapter plate and placed a half inch spacer on the intake. Still have a fluctuation of idle between 900 to 2000. When in any gear it drops to about 400 to 600. Sprayed carb cleaner around carb base and nothing. When it idles about 900 and give any throttle, the motor reaches about 2200 to 2500 and stays there for about five to ten seconds. Shaking my head.

I am leaning towards a meter. Not 100% if it is vacuum related or not.

On a humor side, My neighbor came over when I was working on it and said oh man sounds good. Sounds like you got a big cam in there. All I could do was laugh and think to myself she is supposed to idle smooth.