rogpatt - you have the right idea. experimentation and educated guesses are the name of the game. it is kind of irritating when you have to spend a week fixing something, but when it finally works right it is a satisfying thing. my truck was doing sor of the same thing, the lugging anyway, turned out to be fuel filters. put in 2 new NAPA golds and it runs like a dream. anyway, good luck.
