I believe the biggest problem is the ethanol content in the fuel. That explains why it only acts up mostly on hot days. I bought a little fuel tester to test the fuel from some of the stations around me. The station that I used the most is the local Shell station. It doesn't advertise having ethanol added and the 93 octane checks ethanol free but the mid grade which is what I usually run tested at 10% ethanol. 87 checks ok. Strange that the mid grade has ethanol and the others don't? So far I've only found 1 station with mid grade that checks out ok.
I thought about buying a cheap electric pump and putting it back at the tank just for a test but the more I thought of it I decided if I was going to do all that work I might as well just buy a real good pump and do it once and be done with it so I bought a Holley Gerotor pump. Also upgrading all fittings to Russell high flow fittings. From what I've read the electric pump mounted right at the tank should should help with any vapor lock issues, which I believe this is. I just got the new Holley Gerotor fuel pump bolted in and wiring ran today. Fittings should be here tomorrow to plumb it. Took me a while to save up the money for the pump cause it's pretty expensive.
