Floods after fill up

[jtschug]

I’ve got a weird problem. When ever I stop for gas and the engine is fully warmed up, after I leave the gas station and go about a block, give or take a few hundred feet, the carburetor floods out and stalls the engine.

Has anyone else had this problem and/or solved it?

[stubbie]

By no means an expert on carbs, but maybe check the needle and seat for dirt, wear and float level.

[jtschug]

I replaced the needle and seat assemblies. It didn't fix the problem.

[Alan H. Tast]

May be a fuel pump pressure issue. Newer gas doesn't like to play well with older systems and may be forcing gas past the needle valve. Do a pressure test per the shop manual (jf you don't have one order it NOW!). You may need to install an inline pressure regulator to solve your problem.

[jtschug]

Already installed a pressure regulator and a fuel pressure gauge.

The regulator did help with several issues, I have it set at 5.5 lbs. However, it did not fix the flooding after fill up problem.

[stubbie]

Vapor lock .

[jtschug]

Yes, probably. My theory is there is a slug of gasoline in some part of the fuel line getting very hot during the fill up, but it is down stream of the regulator and needle and seat. Once the car starts the slug moves up the fuel line and after it gets past the needle and into the fuel bowls it flashes and starts boiling venting lots of vapor into the air cleaner. Might even take droplets of gasoline with it flooding the air horn with gasoline.

I'm not exactly sure how to stop this from happening.

[stubbie]

Try some heat shield on the fuel lines.

[Gillerd]

Hope you update us when you found a solution.

[jtschug]

If I find one, I'll update.

Right now working on the electrical upgrade: 3G alternator and relay/power distribution box. Once it is back on the road we'll see if some convolute insulation on the fuel line fixes this.

[stubbie]

JT I can't remember if you have a electric or mechanical pump. If electric I just looked at a youtube video of a guy who was having the same problems you had, boiling fuel and changes in fuel pressure, going lean at idle. He installed a T piece near his carby and ran a return line to his tank and that fixed his problem. if your going EFI you will need a return at some point.

[jtschug]

Currently using stock mechanical pump