View Full Version : Stalling during slow left turn or bumpy road. Hot weather only.

06-13-2017, 04:36 AM
Hey all, any help on this issue would be greatly appreciated.

The car: 1964 Falcon wagon, 170ci, Autolite 1100 carb.

The problem: Ive had this car and have been daily driving it for about a year now, and noticed when I first bought it (last summer), that when the car was running for a while on a hot day (over 75 degrees outside temp), I would stall during some normal left hand turns or when going over a very bumpy patch of road at very slow speeds. Occasionally pumping the pedal after stall would bring the car back to life with a puff of smoke and a heavy gas smell.

I attempted to fix this last year by adjusting float heights, and eventually it went away. But also the outside temps were getting lower as winter approached. I drove it all winter without a single stall on a left turn or slow bumpy rocking of the car. Even when the engine warmed up nice and hot.

Now, summer is coming again and my problem returns. I tried again a few weeks ago to move the float up and down from stock settings and it hasnt done anything to help. Ive thought about putting a spacer between the carb and mounting block, but it seems the studs are too short to allow one. Is my fuel percolating? It always starts fairly easily after a stall, so I sort of ruled out vapor lock...

Im at a loss. I live in a high congestion urban area and stalling in traffic around aggressive drivers is just a rear end accident waiting to happen. Im hoping to clear this up so I can get some summer driving in.

Thanks for any suggestions you may be able to provide.

06-13-2017, 11:02 PM
If it is a fuel percolation issue, check to see if the heater hose is being fed through the base of the carburetor. This was done by Ford as a means to eliminate carburetor icing, which is usually only an issue in fall and winter months. If you drive it year-round, this would be a thing to reinstall, but in the summer months having hot water running under the carburetor may be an unwelcome thing.

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I hooked up a heater control valve in-line on my (now old) wagon to let me turn the water flow on and off without rerouting the heater hose ever year. If you want to use the heater, but not heat up the carburetor, then the heater hose needs to be removed from the carburetor base. You can get a 5/8" hose coupler to join the hose ends together while not connected to the carburetor base.

All that said, the carburetor should not percolate if it is setup correctly, or some other issue isn't present. The Autolite 1100 is a great carburetor when they work right, but from my experience with them, they take a lot of work to get working right. One big failure I see in them is that the main jet and the power valve are all prone to a huge vacuum leak potential, which I outlined here: