1986 Ford Ranger Ranger stauls on hot days

My Ranger runs great when the weather is cooler but once it warms up quite a bit (1/2 hour or so) it begins cutting out and eventually just stalling out. I'm able to restart it after a few minutes but no power. After it cools off for a hour or two it runs just fine again. Replaced the in tank fuel pump, distributer and coil, catalytic converter and oxygen sensor within the past year. The truck sat for almost 5 years prior to my reviving it about a year ago. I had this problem several months ago where it was cutting out but never stalled (not as hot?) And found that when tapping on the module I could either make it run rough or, if it was running rough, make it smooth out. I took off the module and cleaned all the coagulated dielectric grease of, re-installed it, and it ran fine for a few months till it started acting up again. Now I've replaced the distributor and module and am having the stalling problem again. I almost suspect that there is too much heat being genrerated under the hood which is affecting the module. My coolant is good, doesn't boil over and the gage seems to act normally (if it's to be trusted). Any ideas? The mechanic suggested I take the dist/module back and get another one as he feels it may be defective but I have my doubts.