Hi I have a 93 Mazda mx6, it can't idle. When I'm at a stop sign I have to put it in neutral and rev it up a lil otherwise it'll die. I was told from the guy who sold it to me that he washed the engine but turned the car off instead of letting it running causing water to get in the distributor cap. He told us if we took the distributor cap off over night it would dry it out and fix the idle problem. He said it ran great before he washed the engine, it does run great over 20 mph, but under it runs like crap. Should I take the guys advice, or what are other possible reasons for this to happen. Any answers greatly appreciated.