93 S-10 help PLEASE

I have recently purchased a 93 Chevy S-10 w/ 4.3 Z series motor. Lately its 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. Dont know where to go next.
Thanks for all the help !
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"Stein" wrote:

It is possible that you are getting fuel line vaspr lock. Check fuel filter and check fuel pressure too.
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check the EGR value. Might need cleaning.

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I have had the same problem. Change your sparkplug wires.
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Run most of the gas through it and fill up at a Chevron station. It can't hurt to put gas in it without the alcohol.
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Sounds like catalytic converter. "Scott" <homealone.com> wrote in message

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