Quadrajet choke pulloff not working

[83silverado400]

Just wondering why my rear choke pulloff won't work, it is brand new, I have it hooked to lower passenger side port on carb ,I have 12 volts to my electric choke which opens fully ,but I thought when vehicle is first started it should open the choke flap a little, my truck runs rich until the electric choke opens up. Am I hooked up to the right vacuum source? Manifold or ported vacuum.is there any adjustment. Or am I missing some linkage, I have enclosed picture.

 

[Georgeb]

It needs to be on manifold vacuum. Once you confirm that check to be sure the can pulls in like it should. It should pull in fully without pulling tight on the green rod leaving a liitle bit of travel. If when the can pulls in fully it doesn't pull the choke open a bit pinch the U-bend in the black rod a little tighter until it pulls the plate open about 1/4"-3/8". A hand vacuum pump is handy for this. You need about 18"-20" of vacuum.

 

[83silverado400]

The can doesn't pull in at all when engine is running, but if I disconnect hose from carb and suck on it with my mouth, I can get it move in all the way, but the black rod doesn't move at all when I m creating a vacuum. So that means I need to try hooking to manifold source and also adjust the rod. Thank you for your info.

 

[Georgeb]

Its easiest to make the adjustments cold with a vacuum pump. Otherwise it may take you a few attempts.

 

[74 Shortbed]

The can doesn't pull in at all when engine is running, but if I disconnect hose from carb and suck on it with my mouth, I can get it move in all the way, .

You're hooked up to ported vacuum, look for a port that has vacuum at idle.

 

[83silverado400]

I have a vacuum pump at work , I will give this a try this weekend. Thanks for the advice , I'm glad I found this site, so informative.

 

[83silverado400]

It needs to be on manifold vacuum. Once you confirm that check to be sure the can pulls in like it should. It should pull in fully without pulling tight on the green rod leaving a liitle bit of travel. If when the can pulls in fully it doesn't pull the choke open a bit pinch the U-bend in the black rod a little tighter until it pulls the plate open about 1/4"-3/8". A hand vacuum pump is handy for this. You need about 18"-20" of vacuum.

I played around with my choke today ,and put a vacuum on it ,got it adjusted a little better by squeezing the u-bend together a little, but now I have lost my fast idle , it worked before, behind and towards the bottom of the electric choke housing there is a Phillips head screw with a spring, I believe this is the fast idle adj? How is this adjusted? Do I push throttle to floor to set fast idle ,then adjust screw. Thanks for any info.

 

[Georgeb]

Pretty much. When the engine is cold and you open the throttle fully the choke should snap closed and the fast idle came should rotate as well. Thats the piece the screw you mentioned touches. The cam is weighted and has a slot that allows the choke to open while the engine speed stays up until you open the throttle. Then the weight causes the cam to rotate back. When the choke is open that screw should not touch the cam. I used to set mine warm by pushing the cam up to the high idle position and setting my high idle with it running. I liked about 1000-1200 rpm but choose whatever you like.

 

[83silverado400]

Thanks, that will be Saturdays project.