its ur fuel pump or you have a leak in your breaking system which is what i have and when my master cylinder is full of brake fluid my car runs at the best idle and when its tad off it wants to stall ive also noted that when the car is below 1/2 a tank its starts acting up more than normal could be the filter on the fuel pump the lower one. i did change my iac it increased my mpg and my accelaration whent up. i have a dohc 4 banger tho also when my ac is on my belt squeaks but car idles like the queen she is. im thinking the car might be low on freon.
