Chevrolet Repair: 1987 Chevy Blazer - engine shuts off in extreme heat., new computer systems, chevy blazer

Question
I have a 1987 chevy blazer with a 5.7L TBI - 160000 miles on it. I live in Las Vegas, one it hit about 110 and up this summer, my engine starts to cut out. I will be driving along, usually on the highway for about 20 miles and it will shut off with the A/C on or off. It will start back up and run like a dog, until it cools down. The fuel pump was replaced less than a year ago and the sending unit. it's choking on something and I am thinking Vapor lock, I am going to get a new fuel filter and replace that, it's not throwing any codes, its not seizing and my temp stays between 160-170 with my thermostat. Any idea where to look?

Answer
Hi Billy,

I was going to say vapor lock.  Sometimes we can look too deep at these new computer systems, and it is the old basics.  Vapor lock is the only thing that makes sense.  Your vent is probably plugged to the canister...age.  

Next time this happens, loosen the gas cap or take it off.  See if that helps.  

C J S