Hello i just bought a 1991 corolla wagon and in this first week a problem has materialized that did not occur during the test drive. It has happened four or five times but has me worried as a safety issue. While driving the engine seems to lose power. It goes, slows, goes, slows, as if you were taking your foot on and off the gas quickly. So far it has only lasted maybe three or four seconds and has only occured in second and third gear at speeds between 25-35 MPH. Any ideas? Should i try some of the fuel injector cleaners on the market? Also have another question. There is some oil coming out of the valve cover where the PCV valve is. Not alot just leaves a little circle of it around the opening. My manual doesn't mention this happening so i wonder if its something to be concerned about. Incidently the PCV seems to work fine. Thanks you in advance for any help.