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Quadrajet - how to adjust for altitude

I have an old Suburban with 454 and Quadrajet. I do most of my driving in southern Cal at sea level and moderate temperatures. When I go up into local mountains to altitude of 6000 ft., it is very hard to start in cold weather (30 - 40 deg. F.). And once I manage to start it, until it warms up, it runs on just a few cylinders and I have to keep the throttle partway open or it will quit. Do I need to adjust the idle jets leaner when I go up there? I have already confirmed that the (electric) choke works.

Henry

Reply to
Henry
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You can lean down the idle a bit, but most of the time adjusting the choke so that it closes less tightly and/or releases quicker will allow a carbureted engine to work OK at high altitude. If you were planning to

*move* to high altitudes and do most of your driving there, then the main jets should be leaned out as well. But that requires replacing the jets and isn't a quick adjustment.
Reply to
Steve

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