I think my truck was experiencing "Vapor lock" today. It was bucking like a bronco until I shut it down and let it cool off. Once it cooled off a bit things were back to normal. First off do you think this was "Vapor Lock" and secondly, besides switching to an electric fuel pump are there any other suggestions to stop this from happening?
I just bought the truck, but there is only a short piece near the carb and another short piece to the supply side of the fuel pump. I will check under the truck tomorrow for the rest.
Check the vent tube from the tank isn't blocked, this will cause your problem. Remove the cap and it will work fine, put it on again and it will happen again until you clean the vent.
pump in the tank, pressurized fuel system is the best cure. pressurizing the fuel increases its boiling temp point. its the bubbles that keep the pump from pulling fuel from the tank.
Plumbing in a return line to the tank helps a lot. You can use an inline fuel filter right before the carb that has a return line built into it. This will keep the fuel cool enough that it doesnt boil. It doesnt keep the fuel from boiling inside the carb however. But neither will pressurizing the fuel system. There is no fuel pressure inside the fuel bowl past the needle and seat.
Something else that I learned recently to consider. I was talking to an equipment rep. and we were discusing ethenol in the fuel. High amounts of ethonol in the fuel will cause vapor lock. He had a kit that he bought online for about $35.00and checked gas at different stations. Some of the gas had as much as 22% and as low as 5% and I was told by a someone else 93 octane might have more ethonol tha 87.
I remember seeing cars in the old days that use to wrap aluminum foil around the fuel line and stick cloths pins on it??????
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