I have a holley 4160. the car will idle at about 2000 when first started and then drop to about 1300 after a few minutes and will stay there unless i goose the throttle and then it will drop down to 500-750 (it varies). if i then drive the car the idle goes back to 1300. if i'm cruising at say 1000 and depress the clutch the idle goes up to 1300. what do i need to do? i adjusted my choke so that it's almost but not quite closed when the car's fully cold. thanks.

 

Make sure the throttle cable isn't holding it up a little. It's possible the cable or the pedal is binding somehow so the goosing will yank it closed, but "normal" usage won't.

 

Are you using the right bracket for the cable on the carb? It sounds like the cable is binding. Have you tried cleaning the carb? You might have a dirty throttle lever, or throttle plates. Sorry I can't spell for sh*t. What about the strength of your thottle return spring? Just somethings to look at. Hope it helps.

 

How about adjusting the fast idle cam?

 

i'll check out the linkages and cable and spray them down but i have a feeling that's not the problem. the bracket i'm using came with my car so i'm not positive it's the right one but it 'looks' like it's right.

how do you adjust the fast idle cam? i didnt know you could

 

Another thing to check..... Electric choke? If so, make sure it's getting a full 12V or the choke won't heat up fully and the idle won't drop to it's lowest setting.

 

the choke opens fully or just about fully within a couple minutes

 

i hosed the carb down with carb cleaner but that didnt help. this is what it's now doing: when you first start the car and it's fully cold it'll idle at like 1700, if i goose the throttle it drops to 1200 and won't go any lower than that. if i start the car while it's warm it'll immediately idle at 800, if i give it some gas it'll go up to 1200 and stay there until the car is shut off and restarted while warm.

also while it's cold, there is a lot of hesitation in first gear when i first try to move from stop. as soon as the clutch starts to engage the rpm's will drop to about 400 and i have to feather the throttle for a few seconds before power is restored.