Fast Idle
 

I have a 4bbl quadrajet on my SB350. The problem is once the truck is warmed up the truck will still be in fast idle. I can drop the rpm by pushing the idle cam down, but once i hit the throttle the cam moves back up and the high idle continues.

Re: Fast Idle
 

First thing you may want to try adjusting the choke. Manually open the throttle butterflies all the way and insure the choke is completely open or straight up and down. If it's slightly closed it will prevent the cam from dropping.

If that doesn't help you may have a buttefly shaft that's binding. Spray it with carb cleaner.

If that doesn't help, you probably have a flat spot on the shaft. It's a common problem and the only solution is to have a shop drill, shim and replace the shaft.

Re: Fast Idle
 

You need to lean the choke.
Loosen the 3 screws on the black cap and rotate the cap cw. You might need to replace the rivets with screws if yours is like that.
Check this link.
http://www.vetteprojects.com/kstyer/quadrajet_2.htm

Re: Fast Idle
 

I did lean the choke and it still did not help.

Re: Fast Idle
 

When you leaned it did the idle cam drop down?
If you rotate the cap either direction the idle cam should move.

Re: Fast Idle
 

yes when i leaned it the cam dropped to the lowest position. But now when i start the truck it has no choke. If i engage the throttle by hand a little then i can move the cam to fast idle but wont drop back down unless i manually move it with my hand

Re: Fast Idle
 

Now I'm thinking the coil inside the cap isn't on the arm right.

Re: Fast Idle
 

i will have to take the cap off and see whats going on. I pulled the truck out of storage a month ago and has been in storage for 3 yrs