92 Jetta vapor locking?

I've got a 92 Jetta that seems to be vapor locking. It runs fine when it is cold or you keep moving. But sit in traffic and let it get hot and it starts to stall. I can hear the fuel pump start to whine when this starts to happen. If I can get the fuel flowing enough it start running right again. I've changed the fuel filter next to the tank. Anything else I can do? The car isn't over heating.

that's a myth vapor locking..it's the fuel pump related....take it get it presure tested...like i said it's a myth from old day's..good luck..

that's a myth vapor locking..it's the fuel pump related....take it get it presure tested...like i said it's a myth from old day's..good luck..

Why does this only happen when it is hot? If the pressure is low then what do I need to do to fix it?

if presure's low you need new fuel pump..have you changed gas filter if not i'd start there then fuel pump when it's hot fuel pump not working right.
good luck...

if presure's low you need new fuel pump..have you changed gas filter if not i'd start there then fuel pump when it's hot fuel pump not working right.
good luck...

Do you think it is realted to the internal transfer pump or the external fuel pump?

i'd say internal..but really you need a presure tester...good luck...

Test the flow from the supply pump (inside tank). Remove the fuel line and hook a piece of tubing to it and run the tube into a gas can. Remove the seatbelt so that the ignition won't turn over (or disconnect the ignition wire from the starter solenoid) and turn the key. You should be able to hear it flowing. I think it's supposed to pump 2 or 3 gallons per minute. You should be able to fill a can half way in about 10 seconds. Before you buy a new pump, soak the old one in toluene (gas treatment) and rotate it by hand. Also check the coupling that connects the pump to the assembly. It's made of metal and rubber and the rubber breaks down. When this happens, the pump is pumping just fine, but it sends the fuel back into the tank instead of through the system.