Cannot hold idle.

sprink88 · 2012-04-06 10:36

Hey guys. I was wondering if anyone here could have any ideas. My 292 will start but not hold an idle cold. After i got the engine hot by constantly reving it ( not high, just little throttle ) i could maintain an idle.

57tudor · 2012-04-06 14:49

Sprink88.

Sounds like the choke is stuck open. This causes a lean condition with a cold engine. The choke's porpoise is to add additional fuel to the engine and the fast idle cam on the carb opens the throttle slightly to increase the rpm's when cold.
Hope this helps.
Rick
57 Tudor

gasman826 · 2012-04-06 18:01

Just to add a little to what Rick said, tomorrow morning, before you try to start it, take the air cleaner off and see if the choke is closed or mostly closed. Take a picture. Open the throttle plates a 1/4 to 1/3 open by pushing the linkage back and then releasing it. Does the choke close some more? Take a picture. If not, there are several issues related to a 'sticky' choke. First, does the choke open and close with a little resistance (springy). If it sticks, clean the choke shaft were it rotates on the carb horn with a spray choke/carb/carbon cleaner. Hose it right down as long as there is black carbon flowing. With your other hand, cycle the choke open and close while spraying. If the choke plate moves freely. Then you are looking at a tired bi-metal choke spring, a plugged air passage, a rusted/carboned warm air tube. First things first. Check the choke plate first and we go from there.

sprink88 · 2012-04-06 21:53

Well I checked the choke tonight, The choke seems operational. There is about a quarter inch opening just sitting there. I can push the choke open and feel resistance and it does shut with no problem. I think tomorrow I will get it warm, and double check the timing.

lowrider · 2012-04-07 08:05

Like Gasman826 said it may have a "tired" choke spring causing it to fall off too soon. Also when you open the throttle to set the choke the plate should close completely but not so tight that engine vacuum wont pull it open. Getting an automatic choke to work for customers correctly was a black art at times.

gasman826 · 2012-04-07 08:44

It was especially a black art because you only had one shot it. If the vehicle was left over night, you could see for yourself and make an adjustment. Then, wait until tomorrow to see if it needed more adjustment (this scenario almost never happens). There are a couple of 'tools' to artificially cool the choke system down. These tools make it possible to make several adjustment sessions during the same time frame. Huge improvement over the once a day thing.

rmk57 · 2012-04-07 12:19

For pure simplicity and operation you could always swap over to a manual choke.

sprink88 · 2012-04-07 16:07

RMK, that is where I am going if I cannot figure it out.

lowrider · 2012-04-08 05:12

When I worked at an independent shop in the early fall we would cold start a car to see how the choke performed, make adjustments then put them outside with the hoods up to try them again before we left for the day. We might have half a dozen cars sitting out there at times. The regular customers would stop by and say "I see you guys are setting chokes today". That seemed to be the best way to ck them. I've got a manual choke on mine but I'm running 3X2's. I'm confident you'll be able to get yours fixed. Ford's choke system wasnt that tricky with oddball fixes. A few pics might help us.

sprink88 · 2012-04-08 09:23

Well just an update, I have found the idle mixture on the pass side does not do anything. So it only likes to run on the D side, which is fine once the car warms up, because its running leaner then. Makes sense. Venturi's and everything else seem to be operating well. Being Easter, and nobody is up, I would LOVE to work on it but I better take the Prime Rib out of the fridge to get to room temp instead. Happy Easter all. And I will keep you updated on my progress.

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Cannot hold idle.