please help?

I have a 94 camry le with the v6 and it drives a lot better in the colder weather than it does during the daytime when it is hot. I know the engine is getting more air so thats why it would be quicker , but that is not my concern. My concern is the fact that when its warmer and even a little when it's cold the car feels a little hesitant. I just recently changed the plugs, had a freiend at a shop do a free $75 fuel flush, used octane booster, switched to 93 octane. I am no mechanic and am running out of ideas, any good suggestions would be very much appreciated. By the way it has 98,000 miles and I have only had it since 85,000 so I don't know all the prev. maintenance. Thanks.

I'd start by inspecting the inside of the cap and rotor and cleaning the IAC valve.

I'll give that a shot today sometime.
Thanks for the help.