I have recently purchased a 93 Chevy S-10 w/ 4.3 Z series motor. Lately it?s been hot and humid and after driving about 30 miles or so (with OR without the air on) the motor chugs, almost like vapor lock. I was told to run high octane fuel, ran 2 tanks w/ a little improvement, added octane boost, same results. Today was about 25 deg cooler out and had a couple of minor chugs. Don?t know where to go next.
Thanks for all the help !