1999 diesel sub
 

I have replaced everything. INJ pump, oilpressure switch, lift pump, ect, crank pos sensor, fuel filter, and full tank of new fuel with additive. Still getting po335 code and truck is very hard to start, so i believe timing is out of wack. can anybody give me info on key on/off procedure for tdco learn. thanks for any help.

There seems to be a few different ways if you Google 6.5 diesel tdc offset lean procedures, but honestly none of them worked on my 97 after I messed with the pump, I had to break down and run it to a local diesel shop, they didn't charge too much to set it for me.