Autolite-2100

[peanutman]

I have noticed that after about 15 min of sitting my carb is flooding. No visible, juat have to hold gas pedal down and wind a few seconds for it to start. Only does it when hot.
Do i need to do a rebuild, bought truck from orig owner and he can't remember carb ever being touched.
Also i here the 2100 is easy to rebuilt. Any thoughts out there.

Thanks! Robbie

[DuckRyder]

A 2100 is a pretty simple carburetor, as carburetors’ go.

What you have is considered a "hot soak" and might not require a rebuild.

Although it is a simple carburetor I have not messed with many of them, so I'll let the Autolite 2 barrel subject matter experts give you specific pointers...

I'm sure they will be along shortly!

[peanutman]

Thanks duck. Engine runs great except for that. Would like to know what causes this hot soak issue.

[fordman]

engine heat . possible timing set wrong issuse. do you have the carb spacer under the carb that flow water through it? is your gas line all metal from the pump ot the carb. if it is cut a small section out near the carb and put a filter in there or just a rubber hose. that can help also. the spacer is for carb icing in the winter time but can supposedly help heat soak in the summer. the timing has to be just right to keep the engine cooler. as it runs more efficently. i couldn't give correct advise on where to set the timing at. the books say anywhere from 6-8 but others runs there timing all the way up to 12 i have read. so the choice on this would be yours.

[peanutman]

Fordman, carb does have a spacer but water does not run throuh it. This is a 302 if that makes any difference. Line from fuel pump to carb is all steel, maybe thats my problem. My engine runs really cool like around 170-180 and i have put in new thermostat. I have never checked the timing, i haven't used a timing lite in years, i have always just set by ear and engine response.

Thanks for the input guess i will try the line correction. What causes this heat soak anyway I would think it came from the factory with the metal line, what changed to make it start this heat soak issue if it's not the timing

My inline filter is near my fuel pump between pump and tank. No filter on pump-parts store didn't have that one when i replaced the old one.

[fordman]

heat soak is heat from the engine boiling away the fuel in the carb. maybe its the timing. settign it by ear works but a light will help better.

[peanutman]

So is that considered {vapor lock} or {vapor flooding} and is the engine really flooding or carb loosing it"s prime.

[Hawkrod]

It does sound like a heat soak issue but if it has plastic floats they may starting to fail. I would work on heat soak first as it is more likely and can't hurt! As far as when it was new versus now, fuel compositions have changed dramatically and so the way it was new may not always be good enough for now! I would not look to the fuel line from the pump to the carb first though. I would first check the float level if it has not been done in a while. Newer fuels do have different properties and lowering the float just a little will not hurt. Second, timing, this is a very big one. Most heat soak conditions are caused by retarded timing. 10-12 degrees is not a bad point for our engines for initial timing as long as you don't experience pinging and the truck will run cooler (retarded timing allows more heat to remain in the engine and soak in while advanced timing heats up the exhaust instead). Unfortunately setting teh timing by ear won't cut it because it will be running smoother when it is retarded. The spacer without water is good but a thick gasket never hurts. Check the air cleaner duct to make sure the valve is not stuck closed. Look at the fuel line where it runs on top of the frame below the exhaust, sometimes that gets hot and forces fuel to the carb. Finally check the gas cap vent. If pressure is building in the tank when it is warm it will force it into the carb. Hawkrod

[peanutman]

Thanks hawk and fordman for the suggestions. I will check them all out and let you know what ends up fixing it. Guess it's time to by a timing light.

[ScreaminZ]

Also you might check the vent at the top of the carb. On my 69 Mustang, which has the same carb, I had a similar problem due to dirt daubers getting into the carb while it sat and they plugged up the vent. When the engine sat hot, the fuel would dump into the manifold.

[peanutman]

Will check that as well thanks.

[willowbilly3]

I had to put on a Holley to get rid of the problem on my 390. It would heat soak bad, perc the gas out and be flooded, take maybe 30 seconds of cranking. I tried some different spacers and a couple rebuilds and finally put on a 350 Holley asd the problem went away.
I have owned and driven maybe 20-30 FEs and maybe 3-4 of them similiar things.

[rubiranch]

Fordman, carb does have a spacer but water does not run throuh it.

If the spacer is the type with water passages I would hook up the heater hoses to it. The hot water actually cools the carburetor rather than heating it. The exhaust crossover in the intake will get the carb hot enough to boil the fuel.

[peanutman]

Thanks guys i will try all above. Was looking, if i have to change carbs to going with a 4 barrell and stock intake, but can't find a 4 barrell listed for a 302 my year model. Does that mean i will have to go with an aftermarket intake.

If so that worrys me a bit due to the linkage setup cause i have the t-85 od tranny. suppose i could rerig the trapeze or is there 2 barrell holly's available that is a direct swap

[peanutman]

Green, where did you get your holley two bbls and approx cost. Thanks!