nickg

While doing the valve adjustment last night, I noticed that some one has removed the pump before as I can see the marks on the pump shaft, I can also see the groove/keyway in the pump pulley, it looks like its empty? it could be an illusion, and was going to remove the nut to see if it had slipped/sheared the keyway.
has this ever happened and is it even possible, or is it possible the previous person dropped it when installing the pump?
I've been chasing poor performance, (no codes, fresh filters...etc) well more like when you stab the go pedal the truck kinda sits there and after a second or two it starts moving and then it picks up and gets going, almost as if the timing was severly retarded (had this problem on a toyota diesel)
the valves were severly out of adjustment (just like the tranny was) with 300,000KMS on the clock I believe it was NEVER done the intakes were closer to .016-.017, and the Exhaust was over .025

Monty

I have seen a couple of trucks with sheared keyways due to improper installation. On each one, the truck would not stay running under 1100 RPM and missed badly.

While im not saying it isnt a possibility, its usually very rare. I would get a mirror and visually inspect for the keyway to make sure they didnt loose it or shear it during installation.