any codes? check engine light? if not might be the IACV on the backside the intake, it has 2 10mm bolts take it off an clean it out, then re hook it up, an discount the radio fuse 7.5 amp under the hood an about 15 secs later re connect the fuse, an hook the IACV plug an crank it up an see what that does, if it fixes it great if not, you might need to replace it, I have one if needed, thanks Joshua