Hey,

I recently took off my carburetor to inspect for problems. Ever since I put it back on, it has been idling very high. The carburetor is a rochester quadrajet. There are two small screws on the front towards the bottom and one where the throttle is. I have fooled around with them, but can't get the right idle speed. I need to know which one(s) adjust the idle and what the others do/how I should adjust them.

Thanks, Samuel

The one on the side adjusts basic idle speed. The two small ones at the front are to adjust idle mixture; you connect a vacuum gauge to a full manifold vacuum source and adjust those two screws to get the highest steady vacuum reading. graemlins/thumbsup.gif

Look on the passenger side of the carb and locate the choke. Make sure it is not stuck. It will keep the front butterflies open a little bit and it will not idle down. You also might have to adjust it. You should be able to move the arm with your finger and push the butterflies closed. This is just something else to check.

I'd check for the choke hanging up. If it isn't, then check that you replaced the carb base gasket with one that has a stainless steel plate up front. If you don't use the correct gasket with SS plate, air will be sucked from the exhaust passage into the carb primaries, and you will have a huge vaccum leak.
On original first gen Q jet manifolds there is a heat riser under the carb primaries separated by the special gasket with SS plate in it.

Also check the rear of the carb for power brake or smog hoses you may have left disconnected.
David

I had a similar problem that turned out to be a linkage problem. The threaded end of the accellerator rod was protruding far enough to contact a tap on the throttle bell crank. I exteded the linkage about 1/8" and the bind was gone - idle restored.