Carburetor Icing question

[Yellowdart69]

Just curious, when the 318's were new, they developed 'Icing" issues, after a few years, My Dad's '69 Coronet , then my '78 Lebaron, and finally my '82 Cordoba ,all had stalling problems from fall to spring. Until I learned about cleaning the manifold. So I'm curious what 318 drivers do to prevent Icing?

 

[Dr Lebaron]

You're in a warmer and less snow climate than me and having icing issues when all I drive is 318's in the winter?
I think you need gas with less water.

I have more of a chance of the battery freezing, which did happen again last yr.

 

[Jack Meoff]

I've honestly never had that problem.

https://youtu.be/9KXs7BaXg3Q

Maybe it is the gas?
I run ethanol free and I've never had an issue with a frozen carb.
Now I will say my 318 Fifth doesn't like cold but as long as I let her warm up it's all good.

 

[bremereric]

Watch out for the ethanol.

 

[Dr Lebaron]

Is the choke hooked up?
Can see that on one, but not all.

 

[kkritsilas]

Is the carb heat crossover blocked, or the heat riser valve seized?

 

[Monkeyed]

You're in a warmer and less snow climate than me and having icing issues when all I drive is 318's in the winter?
I think you need gas with less water.

I have more of a chance of the battery freezing, which did happen again last yr.

My 83 Bronco used to do that when conditions were just right. If it's super cold out , it's not a problem because the air is so dry. It's when it's bothering around the freezing mark, let's of heavy wet snow coming down that it would do it.

 

[Aspen500]

If the exhaust crossover gets blocked with carbon, besides the choke not opening like it should (unless it has an electric assist heating coil) the base of the carb will get so cold water vapor from the air (not the gasoline) will freeze in the venturi's. This can happen even in 40-50 degree weather when it's damp out. When you run fuel and air through a venture it drops in temperature a lot. The frozen vapor will block the idle ports at the very least. Worse icing can cause the throttle to stick open. The icing isn't as much of a problem on cars with properly functioning hot air intake systems.

Living in north central Wisconsin I can remember carb icing well and also the causes. This applied to not only Mopar but GM and Ford as well. Blocked exhaust crossover and/or inoperative hot air intake happened to all of them. I'll bet I probably pulled a couple hundred intakes to clean the crossover out "back in the day" at work (auto tech) Don't forget, that was WAY before they put ethanol in gasoline. Cars built before hot air intakes can get carb icing even with a clear crossover and functioning "heat riser" valve. At one time, it was very common and just considered normal.

 

[Cordoba1]

If it's a stock setup, like others have said, check the hot-air system. Do you still have the metallic hose that goes from the heat-stove to the intake side of the air-cleaner? If not, put one on. The thermactor on the side of the air-cleaner delivers vacuum to the hot-air inlet until the incoming air is 90 degrees. The system works hard to keep the incoming temperature to within + or - 5 degrees of 90. This accomplishes two things: Provides enough heat to keep the carb from icing, and it also provides a baseline air-density to which to calibrate the carb. Your car will exhibit much better drivability with this system working. I had much trouble at low temperatures until we finally found a $10 thermactor that was faulty.

 

[Yellowdart69]

I don't have the problem, anymore, but that is because , now I only drive my 318's in good weather. I was just wondering what other's do as the weather is starting to cool and damp.

 

[8v-of-fury]

Just curious, i want to get the hot air system working on the 88 5th again.. It won't be driven too much in the snow.. but I may drive it on COLD days with no snow haha.

How does that system work? it gets manifold vacuum to the "thermactor" on the air cleaner and then that is a temperature controlled switch that regulates the flap in the intake snorkel.

 

[Cordoba1]

That is exactly right!

 

[8v-of-fury]

Straight up manifold vacuum? hmm, i'll give it a shot

 

[8v-of-fury]

So the red gets manifold vacuum, and the heat sensor guy in the air cleaner then sends vacuum at the right temps to the door in the inlet?

 

[BudW]

Here is some data I found on the system – but not a peep of details about which port to hook it up to.

I “believe” the vacuum source hose (from carburetor) attaches to port the opposite end with the Red arrow in picture.

I will look when I get home to verify.

BudW

 

[8v-of-fury]

BAM, right here on the top of the left. It states, the second snorkel of a dual snorkel air cleaner will be TEE'd in to the line between manifold vacuum and the air sensor. BOOM lol

 

[BudW]

I misunderstood your question. I thought you wanted to know when port of the temp sensor/switch gets manifold vacuum.

BudW

 

[8v-of-fury]

oh hah! I can't see it mattering eh?

 

[BudW]

Well, come to think of it, it might not matter, which port gets manifold vacuum.
I don't know exactly.

 

[8v-of-fury]

I am pretty sure it is just a thermostatic air valve. So I can't see it being direction dependent.