Lastnight i went to a friends house with my 74 maverick with the 250, and there was snow blowing around, and its 10 degrees outside, well i was there for a couple of hours and when i went out side to get in a go home my throttle was frozen solid, i pushed hard and broke it loose but then it stuck open so i got out and pushed it back to the idle position and went to set the choke and it all fell apart, but i can fix the choke, but i dont know how to keep the throttle from freezing, and after all that i only had about 1/4 throttle until it completely heated up, which took like 15 minutes or so, any ideas on what i should do?
Do you have the stock air filter assembly on it??? If so is the heat stove tube still attached to the snorkle and the exhaust manifold...If not get it working properly.Its purpose is to prevent the very problem you are experiencing...
I'd start by lubing up everything that can be reached, maybe adding a return spring (or a stronger one). Carb rebuild might in order, as what may be sticking here is the bushings where the throttle plate pivots. Either they themselves could be sticking, or just allowing enough play in the hinge for the plate to stick against the bore. Could also be none of that. Could be the cable or even the pedal, so check all that too...
some cars also had a bracket that routed the "hot" side heater hose against the choke body. I suspect that added a little heat as well, but the heat stove is the most beneficial. a good shroud that goes around the manifold is absolutely necessary for that to work. most also had a small tube routed to the back of the choke mount on the carb from the exhaust manifold to heat the choke as well. All of mine have been V8's with one exception and they all have had all of these components.
the heat stove is in place but the valve doesnt open on the air cleaner, it has vacuum to it though, can the diaphragm be replaced there? and all of this happened before i could even start the engine after it idled a while it all worked its way out, and i have a manual choke on there, it was the only way i could get the high idle to work, because with the automatic choke, when i would get the spring with enough tension on it to set the high idle, it would starve out the motor of air to much and would not run, so i put a cable unit on there, id like to have the automatic but i didnt know if maybe the spring was bad in there or what ever, but i had thought about spraying everything down good with WD-40 good or bad idea?
A thought, being a small plane pilot, there is a condition known as carburetor icing. It is where the humidity in the air freezes on the throttle plate itself. As fuel is mixed with the air in your carb the temperature drops due to the fuel evaporating. Ok, did you just drive a short distance and park? If this was the case the snow probably melted and refroze on the external linkage. You could have also gotten carb ice. To determine which, just look at the linkage. Don't see anything?, take off the air cleaner and hold open the choke and look into the carb with a flashlight. You will see " snow " on the throttle plate, if this is the case. The bad thing with carb ice is you can bend the throttle plate by forcing down on the pedal. Then your idle will be all out of whack and probably to fast! The cure for both these conditions is to make sure the engine is fully warmed up before you turn it off. As others have said, make sure your preheated air cleaner works. This is almost imperative on a Ford in conditions below 40°F.
Ok i will see if i can replace that vacuum valve so that it pulls hot air, because as of now that valve stays down and only pulls cold air, and i drove it about 6 miles then shut her down, but it wanted to stick a little even after i drove it 80 miles, how do you replace that vacuum diaphragm?
