Problems with a Detroit 12.7.

2003 Freightliner 12.7 Series 60 Non Egr.
The truck will just loose power at times usually going up through gears.
When the power finally comes back (in a few seconds usually) then the truck doesn't come all the way back to idle quicly after letting off the excelerator. The truck motor hangs at about 1300 rpm or so blowing the gear change.
It runs really good the rest of the time. 430/475 Any ideas?

 

Air sucking from leak in fuel line?
I had a spot on the filter that looked like it was dripping from time to time but I took care of that.
Any ideas where to start looking after that?

 

Canister
Fuel pro

 

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I pulled the TPS out and on the bench it seemed to be fine. I was looking at it with a old analog vacuum tube VoltOhm Meter and it's as smooth as butter except at the very first part of the stroke where it snaps on like a switch and the comes to rest at about 700 ohms and then is smooth as butter up to about 2200 ohms, end of stroke. I have no idea what it's actually supposed to be? Maybe it should be 0-2200 ohms? I just figured it was working correctly but maybe it's not all there. Anyone ever test one of these TPS's on the bench?