I have a 57 F100 with the 272 Y-Block/ manual 3 speed, when I come to a stop the engine is idling high I have to hit the pedal for it to rev down so I can put it in 1st, but when I do that the idle drops real low like to the point of almost shutting off, this is constant I have to hit the gas pedal for it to rev down...carb stamped numbers are C2AF AH which denote a Autolite 2100. PO said he rebuilt the carb. Any input?....thanks If I need to rebuild myself anybody have a good source for quality parts?
Fast idle on the choke is sticking, I solved this on mine by changing from automatic choke to manual. Sent from my iPhone using Tapatalk
Or the throttle shaft is loose in its bores allowing the throttle plates to stick or the shaft is loose in the primary linkage arm , or the fast idle cam is sticking or your return spring is weak or the counter weights in the distributer are sticking or the vacuum advance is sticking .......
http://www.thecarburetorshop.com/Carbshop_kits.htm @carbking here at the HAMB should be able to hook you up. Download the 2100 .pdf manual and study it. They are pretty simple but everybody screws 'em up because of failure to follow instructions.
Check that the choke butterfly is vertical. If not, then the fast idle would be engaged until you kicked the throttle. It also sounds as if the curb idle RPM is set too low. If the carb has a separate (from the fast idle) idle setting, ALWAYS wait until the engine is at operating temperature, and the choke butterfly is vertical (wide open) prior to setting the curb idle RPM. Jon.
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