Quote: Nope. No power valve. That's the reason I went with one while I rebuilt my Holley after it was causing problems..
maybe it's NOT the carb then. Start from scratch. turn the mixture screws all the way in, then back them out 1 full turn. Next unplug your vac advance and get your timing light and vacuum gauge out. Start the car to where it will idle. Turn the mixture screws out until you get the best reading...set you idle where you like it, Then take the car up to 2400rpm and set your advance in full 36-38* should be good. Now bring the idel back down and re-check/re-adjust for best vacuum. Maybe you need a hotter plug. oh and MAKE SURE YOUR FLOAT LEVELS are set.
