Starts rough, used to warm up & smooth out, *. Now staysrough, used to idle fast, used to slow down to normal when I turned engine off at stop light & restart. Plugs & wires check out good when interchanged, been reading up on it & it indicates that it is a vacume leak somewhere behind # 1 cylinder? [ Fast idle & rough running] I have no idea where or what i'm looking for or how to test for a leak, [ hose, line, gasket, valve]? If I was to use smoke, would it be visable to the eye if it distorted the air round the leak? This is my wifes car & other than that it runs great, can't be too serious as some times it clears up & runs excllent. Does not burn oil & gets 42 mpg. Last summer when I changed the plugs, # 2 [from left] spark plug "well" was 1/2 full of oil with no visable leakage anywhere, could this have been a cam cover 'top" gasket leaking? Did not affect to performance in any way. No oil was spilled as I am the only one that "services the car. This problem is no more.