Vapor lock in Tucson

I live in Tucson AZ and after driving for about 20 minutes in 100 degrees or above my 1981 stick shift vapor locks and won't start after being turned off. It will restart after cooling for about one hour. I've wrapped the lines on both sides that run parallel with the manifold that carries fuel to the ejectors and some others with material I've gotten from Pep Boys. The material is designed to dissipate heat, this has not helped. I have been told it might be the fuel pump not putting out enough pressure, but it was replace along with fuel filter in May 2011. I need some guidance on what to do next. If I was to check the fuel pressure how would I go about it and what is the correct PSI required?

It was suggested that I louver the hood I guess this would dissipate the heat the question do I use one large of two small and what size?

Any help is welcome
Patrick Fitzpatrick

Take off your gas cap just to relieve and suction that might have built up. Be sure your gas tank is full, then check fuel filter and see that the fuel pump is shielded from heat as much as possible and that it is working correctly...

Hopefully Wally will jump in here in a bit as he is one of the 928 masters around here!

BTW, Emerald lives in Tucson and is a true 928 enthusiast who owns many of them...just up the road in Phoenix is a GREAT 928 group led by Rich Andrade and of course one of the best 928 shops in the country is right there in Phoenix as well!

The problem might not be vapor lock. The next time that it happens, push the throttle to the floor and leave it there while you try to start the engine. If the engine starts, the problem is too much fuel when hot, not too little.

Wally, I would like to say that you are doing a great job, no an awesome job at helping others and answering their questions.

PLEASE dont stop.

Brad

It was suggested I drill a 3/16 hole in the gas cap. Have you heard of doing that?

Would not suggest drilling a hole in the gas cap... If your car is running right (and clearly something is up) you won't need it and it is unlikely that it will help and you will just ruin a very expensive gas cap. Also if your car is required to meet emissions standard where you live that will be an automatic fail there...