I just purchased a sweet 1973 Super Beetle and managed 100 miles before it quit running. I pulled the inlet to the fuel pump and it was bone dry, so even though the guage read half full, I thought it ran out of gas. I poured in a gallon, and it started and drove home. Next trip I got two blocks from home before it quit and wouldn’t start. I towed it back home, and the next day, it ran like a champ. The fuel should flow freely into the fuel pump, right? What could be causing this occaisional fuel starvation?
IIRC this year is still carburated with the fuel pump mounted on the engine. If so, check the strainer at the bottom of the tank up front for debris clogging. Also replace any fuel hoses on the suction side of the fuel pump. In fact change them all if the hoses are fabric covered as they can look fine but disintegrate underneath the fabric.
Put a vacuum gauge on the suction side of the fuel pump and verify that it will pull and hold a vacuum. Finally, lightly pressurize the gas tank (0.5 - 1 psi) and search the entire suction side fuel line for seeps. You are looking for anywhere fuel is seeping out as that is where air can leak in and break the suction of the fuel pump. This beetle is old enough to have rusted out steel fuel lines so pay attention to areas that are excessively rusty.
Hope that helps.
Thanks…I’ll try that this weekend. One verification: when I take the fuel line off the suction side of the fuel pump, should fuel be spilling out the steel fuel line from the tank? When I’m having trouble, no fuel is trickling out; when the Bug was behaving, gas would flow out of the steel line via gravity.
With this information, I would look at the venting for the gas tank. I don’t remember if the '73 had a gasoline vapor recovery canister. But, somewhere there will be a way to relieve vacuum buildup either in the gas cap, a hose from the tank filler neck, or a hose to the canister. One way to check to see if this is a problem is to take the gas cap off. If there is a sound of air rushing in and the beetle now starts and runs for a while, that could be your problem.
Keep us appraised of your progress and what finally solves this problem.
Remove the hose where it exits at the divers side (rear) transmission mount,if they are going to flow by gravity they will at that point.