Ontario69Hurst

I'm having problems with cold starts. The Quadrajet has been rebuilt and runs perfectly at all other times. I believe the the cold idle adjustment screw needs some tweaking. A single pump of the gas pedal engages the choke plate properly.

Can anyone with a 69 HO tell me how screw turns out their idle screw is set to.

69 Hurst

I've had this same issue since I got my car. Hoping someone has an answer.

joe_padavano

You don't set it based on turns, you set it based on RPMs at a specific set of conditions. 1969 Chassis Service Manual, Page 6M-43. The fast idle adjustment procedure is spelled out in box 12 in the lower RH corner of the page.

Sugar Bear

The cold idle speed is set by RPM with a tachometer with the idle cam on a specific step. Setting it by how many turns another is set at probably won't even get it close.

Remove the air cleaner on a cold engine, watch the high idle cam while opening the throttle to confirm that the high idle cam moves when the choke plate snaps shut.

If the cam moves and a tachometer isn't available, turn the high idle cam inward one half of a turn at a time until an acceptable high idle speed is obtained.

Good luck!!!

Sugar Bear

Joe, You type tooooo fast!

Sugar Bear

Following a factory service manual step-by-step on a Qjet will make you and your car very happy.

Ontario69Hurst

Purchasing the manual would be a good investment. In the interim I will try the adjustments that Sugar Bear has given.
Thank you

joe_padavano

The proper way to adjust the fast idle is to bring the engine to operating temperature and then manually position the adjusting screw on the fast idle cam. You then set it to spec. This is the only consistent and repeatable process.

nicks1966

dragline

Is the choke pulloff opening the choke flapper? This has a major impact on cold operation. It also controls opening rate of the secondary flapper.