After I owned the truck for a few days I noticed it was missing a shim from one of the barrels. So I checked the rest and most of them were loose. There were no signs of the Barrels being adjusted. So I snugged them all and it was hard to start it without giving it some pedal and when I did get started I missed badly, worse in gear. I even went back and adjusted( snugged/loosened) them while the truck was idling in gear with the parking brake on until it idled smooth. I also changed out the stock 131s for some 026s in August -same thing , loose nuts = smooth idle, torqued = barely start,idle,bad miss. I also put in some rebuilt 215 injectors in September of 2012 - same issue. So I racked the barrels since I figured the pump may be out of balance anyways. But it does idle/run smooth with the nuts barely tight enough to hold the barrels shims from sliding out. There is one place in my state that can balance p pumps. I just wasn't sure if it was a pump balance issue or something else.