BAD carb ice

[Dicipleofthelie]

yesterday after work i was driving home and my car began to act strangly.
throttle sticking.....serious loss of power in all gears....it got to a point where no matter how much i pumped the gas....nothing would happen.....it would just idle very rough then die

took me about 10 minits to get it started again

ive had this problem many times with this car....i know for a fact that its carb ice....but i have no idea how to fix the problem........

any suggestions?

[pdrover]

Move south?

[brink]

You mean ice in your carb? Hrm... *thinking*

There's some kind of hydrophobic spray that a mechanic sprayed into the distributor cap on my old mustang to solve a moisture problem... I don't know what the stuff is called unfortunately. I would think that could solve the problem -- no moisture == no ice. 'Course, I don't know if it's safe for carbs or not.

[|PuNiSh3R|]

Hey, disciple.. I thought you were still with the stock carb? If so.. the stock intake manifold has water channels in it.. that allow the coolant to flow into the manifold and into part of the carb to keep it from icing.. Other than that the only thing I could think of would be to tap off of a coolant line.. and use a small copper radiator or a small heatercore under your hood.. right next to the carb and use a fan like a computer fan.. a 120mm one.. and have that blow the heat from the coolant system on the carb or the area..

[Nick]

as mentionned above there should be coolant passages though the carb to warm it up, they could be clogged,

if there aren't you could make yourself a little heating system (copper tubing wrapped around it) or you could have a spiral of copper tubing in your intake tube

with high humidity and temperatures near freezing it happens to all carbs

[|PuNiSh3R|]

yea, except those that feed their intake charge from pretty much right by the engine.. as in, no intake piping.. I think you'd be better off with my under the hood heatercore idea though.. be easier to do .. I mean you don't need very much to keep the carb above freezing.. It must have been really cold out for that icing to happen.. I've driven my 4AF with the Weber carb on it in 0F weather and never had that problem.. I was still using the stock manifold though and It still had the water passage in it.. so it warmed the manifold up.. but it was plugged at the carb since the weber doesn't have water passages.

[Nick]

you guys don't understand how carb ice forms, this is something quite common in aviation, we have an alternate intake that is routed through the exhaust to warm up the air

here's a brief speal about carb ice, there's tons of info out there about it, mostly related to aviation though

Float type carburetor icing is possible when atmospheric conditions have a relative humidity of 50 percent or higher and a temperature range of 20oF to 90oF and under the right conditions with a temperature of as much as 100oF. Rapid cooling of the float type carburetor is caused by the absorption of heat during fuel vaporization and the high air velocity causing low pressure in the venturi. Reduction of air pressure causes a drop in temperature. As a result, the temperature of the mixing chamber of the carburetor may drop as much as 60oF.

If this area contains enough moisture, the cooling can cause precipitation of the moisture, usually in the vicinity of the throttle plate, where it can freeze on the plate to the extent that a drop in power could result. If not detected and corrected in time, it can cause complete engine stoppage.

[|PuNiSh3R|]

ok that explains it.

The stock 4AF setup actually has an alternative intake from the exhaust manifold insulator..

[Nick]

ok, so there's probably a vacuum line or something that makes it flip over, you might have a leak or the diaphragm might be too old and cracked

[|PuNiSh3R|]

Actually I think it's a cable.. not positive been a while since I ripped mine off.. It is basically there to get the engine to warm up faster by heating in the intake air.. there is an actual heating element on the side of the carb that is used for de-icing I think.. if I had my manual on hand I would look.

[Dicipleofthelie]

yea...actually my problem is just like aviation carb ice......planes have carb heat knobs and stuff.......there used to be a tube that went from the exhaust mani up to the intake.......thing.......i think that may be a major culprit

[Dicipleofthelie]

ok, installed a high temp heat riser hose to the snorkle from the exhaust yesterday...............cars still doing the same stuff.........rough low idle not wanting to stay running...........complete lack of power in most gears due to iceing...........much bas stuff..............GAW DAMNIT

[Flashmn]

Howbout putting some anti-ice in the gastank... thats what we do here near the arctic.

[Dicipleofthelie]

that heat stuff?

meh...worth a try......but thats only a temporary fix.........i still think the carbs effed up

[|PuNiSh3R|]

Uh... so right.. are you SURE it's from carb ice?