I am having a hard time figuring out how to drop my 1979 Pontiac Catalina's V8 down into low idle speed after it's warmed up. The idle goes up when it's hot, like it should. I've tapped the gas pedal and it doesn't drop down.
Well it could be your choke is sticking see if you choke is sticking it has an electric choke it might be burned out doesn't even work anymore there's just a screw on the idle on the throttle part of the carburetor that once it's warmed up if the choke opens the whole way once it's down like that you unscrew it but you can then again you might have a vacuum leak or you might even have a carburetor problem if it's old and dripping too much gas it won't idle right it might need rebuilding
Try manipulating the choke linkage manually to see if it's sticking somewhere.
Make sure the choke linkage is clean and moving properly (carb cleaner.) If it's electric, make sure the coil connection is good and the choke plate is opening properly when current is applied. When you initially set the choke, the throttle plate will sit on the high step of the choke cam and as the plate opens, it should come off the high step and idle about 750 rpm.
