CARBURETOR 72 VETTE

[Michael C.]

I HAVE A STOCK 1972 VETTE WITH A 350 ENGINE AND STOCK QUADRAJET CARBURETOR. THE PROBLEM I AM HAVING IS MAINTAINING A CONSTANT IDLE SPEED. SOMETIMES THE DARN THING WANTWS TO IDLE TO LOW [ 400-500RPM] AND OTHER TIMES IT WILL JUMP UP TO 1200-1400 RPM. IF I REV THE MOTOR FROM THE HIGH IDLE ,SOMETIMES THE RPM WILL DROP BACK TO THE PROPER 700-750RPM RANGE. I HAVE REPLACED THE THROTTLE RETURN SPRING, THAT DIDNT HELP. ANY IDEAS ??? THANKS IN ADVANCE. MIKE C.

[Harmon C.]

Re: CARBURETOR 72 VETTE

Are you seting the idle with the non dieseling solinoid adjusting bolt and not with the linkage on the carb? Also please post without( caps) we consider it shouting.

[Clem Z.]

Re: CARBURETOR 72 VETTE

worn throttle shafts or the bores where the throttle shafts go thru the base plate will also cause this problem. both these problems can be repaired by a good carb repair shop.

[Michael C.]

Re: CARBURETOR 72 VETTE

Im setting the idle with the adjustment screw that either retracts or extends the linkgage, ie what I thought was the idle screw. Is that wtrong ? Mike Chase

[Harmon C.]

Re: CARBURETOR 72 VETTE

The solinoid is on the left front and has a large hex bolt that may be1/2 inch and this where you adjust the idle.

[Patrick H.]

Re: CARBURETOR 72 VETTE

I agree with Clem.

Another source would be a vacuum leak somewhere in the vacuum system. On my 71, it turned out to be a minute leak of the intake to the heads. I chased it for 6 years before I fixed it.

Patrick