VCCA Home Forums TECHNICAL - GENERAL Mechanical - Engine, Trans, etc 41 idle rough/stalling after running great for a long time

My '41 has been running like a champ for 18 months or so. Yesterday I took it on my longest drive ever (probably put 120 miles on it) and about 2/3 of the way in I started to see it idling rough, stalling at lights (if I didn't keep giving it some gas), etc. I ran the fuel a lot lower than I usually do...probably under 1/4 tank. Wondering if I sloshed some sediment around (my tank has been replaced and cleaned out by me). It runs great at anything above an idle. My fuel pump was replaced about a year ago. I have a glass bowl fuel filter just in front of the carb that visibly looks ok.
I'm guessing the idle jets are clogged?
I've been pretty hands-off so far messing with the carb. Is it as simple as taking the idle adjustment screw and the nearby plug out and flooding with carb cleaner?

I agree with your thinking that there is dirt/sediment/whatever in the fuel system. Even after having it cleaned twice the tank on my ”˜37 continues to “shed” very fine particles of what looks like rust. They are so fine that they would pass through the screen on the fuel pump. They would accumulate in the float bowl of the carburetor. Eventually it would affect the idle.

I have a replacement Carter YF on my car so it was pretty simple to clean it and get things going again.

I have added a Fram G2 in-line filter just beyond the outlet from the gas tank. I can see when it is almost full and needs to be changed. I have not had to touch the carburetor since I added that filter.

To clean out idle jet place #3 spark plug wire on #4 cylinder and # 4 on # 3 cylinder, Remove aie cleane, start engine andstomp down on gas pedal several tome. The back firing will blow the dirt out of the jet.

Thanks Gene. I remember that trick but I couldn't find it in my post history. I will see if I can get down there and try that today.

Thanks Rusty. I don't have a filter before my fuel pump, but I have one of the glass bowl ones just before the carb. Maybe one of the canister ones have a finer filtering capacity that the one I have. I think I bought a bunch of filters, lemme see what Gene's trick does for me first. I've got some cracked ribs and a broken collarbone (long story)....so getting under my car is about the last thing I want to do right now :)

UGH! That sounds pretty uncomfortable at a minimum! Take it easy.

I agree that it is easy to try Gene's trick first. I assume you are running a W-1 of that generation.

The filter before the carb should at least give you an indication of dirt issues.

I know this sounds crazy but one thing I have to do about every 1000 miles is "snug" the float bowl screws on the carb as well as the nuts that mount the carb to the intake manifold. The clue is that the engine does not start quite as quickly.

Gene's trick for the win....as usual. Thank you as always.

Thanks Rusty. I had to get back to work, but will put checking carb tightness on my list when I feel like bending over :)