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Rochester Quadrajet Choke Adjutment

7902 Views 2 Replies 3 Participants Last post by  Schurkey
I just rebuilt my carb. and am still having the same starting issue, thinking the accelerator pump was bad. I sealed (epoxied the fuel bowls) and threw in the rest of the kit. I still need to pump the pedal 10 times before it will start. I cannot remember how to adjust the automatic choke properly. It seem that the fast idle cam is not flipping to the top of its travel, I manually place it there it starts and runs very well. I have messed with the adjustment on the choke cover but I want to get it right, its a hassle to open the hood to set the thing every time.
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What he said. The instructions come with the kit.

Short story: (Assuming a stock or mild-performance camshaft) an automatic choke needs to do four things:

1. The choke coil should be adjusted "somewhere near" the index position. Even divorced choke coils can sometimes be adjusted. At any rate, the coil is adjusted so the choke OPENS at the appropriate rate. WAY TOO OFTEN people screw with the choke coil trying to get it to CLOSE in a manner that suits them; or they screw with the choke coil when the problem is really in the choke pull-off.

2. The choke pulloff should be adjusted so that it pops the choke blade open "about" 1/4 inch as soon as the engine starts. The engine should NEVER gargle on gasoline; and it should not stall or sputter.

3. The fast idle cam should be adjusted (syncronized) to the choke pulloff so that when the pulloff pops the choke blade open, the fast idle cam drops to the second-highest step from the highest step.

4. When the throttle is opened fully, the choke blade should be forced open about as much as the choke pulloff would open the blade--probably even a bit more.
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