My truck has idled wierd since I bought it; it irradicly goes up and down between 500 and 800 rpm. I thought it had something to do with my injection or lift pump since the were both bad, but I have since replaced both (lift pump is a fass) and it still idles funny. What gives? Also it seems like the truck really labors to get up to speed. What I mean is I have push down on the pedal really hard to get her to go.