What exactly happens to the fuel in a diesel to get it into the injector. I hear cp3 lift pump... all that but can someone give me some insight or a link to do some readin on the cummins fuel delivery. Whats a cp3 and exactly what is a lift pump. I know ur supposed to change the spark plugs every 20000 miles but other than that i got nothing? hahaha just kiddin i know how the engine works just not the fuel delivery system.