fast idle

[markzepp820]

I have a 79' C20 with a Carter Quadrajet. I'm wanting to know what makes the fast idle, kickdown, when in Park of Neutral? When in park, idle is 800rpm then when I put it in drive its at 500rpm. What do I have to adjust to make it kickdown to 500rpm in park when warm?

[Z28 c10]

500 rpm's is too low when in park. If you idle down that far she's going to want to stall out, especially if you have AC. There is no way to have the same idle from park to drive.

 JayTater

 Z28 C10

Edited by: Z28 c10 at: 4/3/06 8:54 pm

[DnStClr]

The 800rpm idle speed is right where you want it to be.

[markzepp820]

Okay. But what causes it to kickdown when you tap the pedal when in park. I'm wanting to adjust my carb to where it idles fast when cold(like 1200rpm or what ever the specs are) then kicks down to 800rpm while in park. Where at on the carb do I adjust this?

[123 pugsy]

I believe what you want is your automatic choke working.Do you have a repair manuel? If so,it should have all the carb setting info. Automatic choke cover is black plastic which you can turn to adjust if the factory rivets have been drilled and replaced with screws. This is an Edelbrock carb by the way.It won't look like yours exactly if you have stock but they all generally work the same.




Your carb on the drivers side may have only 1 screw for idle.The Edelbrock in the photo has 2.Pink arrow is the adjustment screw that rides on the Fast Idle Cam (yellow arrow).If you don't have this screw your idle adjustment screw rides on your fast idle cam.(its curved with steps on it)
This is where you get the high revs when you start it cold.When its warmed up you can "kick" it off.




Anyway,carbs are a pain in the @@@,and there are a bunch of adjustments to make.Hard to describe them here.Thats's why I mentioned the repair manuel.Haynes,Chilton.....

[markzepp820]

thankyou