1974 Volkswagen Beetle Vapor Lock

One thing you could try is if you've got an in-line fuel filter, especially the OEM type, replace it.

Replaced fuel filter, fuel pump & fuel lines. Still after driving about 15 minutes, engine starts to sputter & backfire. Pour cold water on the fuel pump & splash some on the the carb & off I go.

Check the choke? My 74 super beetle had a faulty choke, the wire connection was cracked, and the spring mechanism inside was no good. I replaced it and haven't had any problems since.

Did you replace the fuel line from the tank to the chassis? On mine there was another filter there, I do not know if it was there to begin with, or an aftermarket precaution. Either way it helps keep the crud from the leaded fuel these cars once used out of the line before it goes to the pump to clog it up and cost even more money.

Also check to make sure the v-belt is on firm, sometimes as it heats up they stretch, and it doesn't cool the motor properly.

Make sure the engine tins and seals are on also, with the heater openings plugged or tunnelled outside the engine cavity, overheating cracks the block, and magnesium blocks that they used in VW's get harder and more brittle with the higher temperature they are exposed to.

Next time you go to pick up parts, go to a VW specialty shop where they work on classic VW's, those people are normally very generous when it comes to troubleshooting.

I'm having the same issue with 1776cc motor. I can go about 20 minutes when the temp is is in the 90s. I replaced the mech fuel pump with an electric but it still has the same issues. Did you do anything with your choke?

"Air Force" John