What does a choke pull off do?
Thread Starter
Le Mans Master
Joined: Oct 2006
Posts: 8,939
Likes: 35
From: El Cajon California
What does a choke pull off do?
I have just read Lar's New Tech article "How to Set Up a Q-Jet Choke" and will put this to good work this weekend on a 1978 Vette.
While studying it I am trying to figure out the role of the choke pull off.
BTW - Lars wherever you are thanks!
While studying it I am trying to figure out the role of the choke pull off.
BTW - Lars wherever you are thanks!
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
The choke plate needs to be completely closed to "choke" and draw fuel in but once the engine fires it needs air so the "choking' needs stop and the the pulloff opens the choke plate a little and lets air in.It pulls the choke off or open.
Tech Contributor
Joined: Aug 1999
Posts: 14,370
Likes: 6,361
From: At my Bar drinking and wrenching in Lafayette Colorado
The choke pulloff does exactly what DWncchs describes - it cracks the choke open about 1/4" once the engine starts, to prevent the engine from flooding out from the fully closed choke plate.
On a Q-Jet carb, the pulloff additionally acts as a secondary airvalve opening rate controller or damper. Think of it as the damper on your front screen door on your house: The spring on the door produces a "preload," but the damper keeps the door from "flopping" or "slamming" open at an uncontrolled rate. The pulloff, thus, helps produce a smooth secondary transition on your Q-Jet carb.
On a Q-Jet carb, the pulloff additionally acts as a secondary airvalve opening rate controller or damper. Think of it as the damper on your front screen door on your house: The spring on the door produces a "preload," but the damper keeps the door from "flopping" or "slamming" open at an uncontrolled rate. The pulloff, thus, helps produce a smooth secondary transition on your Q-Jet carb.
