6.5l td rough running under 1500rpm when warm

[angryratchet]

Greeting,

I'm hoping yall can help me confirm my suspicions. I got this 97 k3500 6.5l td as a shop truck. It had been sitting for nearly three years. Once I got it running it ran great, I decided to drive it until i ran the old fuel out and fill with a new tank. after i filled the tank i got about three miles down the road before a check engine light came on. when i came to a stop it started running really rough, got hard to start and stalled, lots of white smoke.

I did notice i smelled burning plastic. when I got home I checked under the hood and sure enough the turbo vaccum line had melted because the last owner routed it across the hot section. So i fixed it and it ran great again... or so I thought. i test drive it and it starts doing it again. I changed my fuel filter because i thought there may be contaminates but that didnt fix it either. I hooked up my scanner and had two codes. P1214 "injection pump timing offset" and p0216 "injection timing control circuit". I checked those on shopkey which lead me to monitor the injector timing. it was reading fine. I decided to drive it until it started having problems again. i parked and looked and my actual time said 0.0 with 13 at idle. using my scanner i set idle to 1500rpm. the desired time increased and the actual time stayed at 0 UNTIL i got it above 1500 rpm. at which point the truck stabilized. I'm thinking either pdm or optical sensor?

TL&DR

Runs like crap above 170 degrees temp
Runs fine over 1500 rpm
Codes p1214 and P0216 active and dont go away
Monitoring injection timing shows actual at 0 when having problems until 1500
fuel filter, air filter, glow plugs, batteries and oil is all new.
Fuel is fresh.
is a pump mounted PMD

Edit: actually I do have a remote mounted PMD but when i plug it in the truck just cranks and doesnt even try to start, it does have the resistor in it. if you have thoughts on that too I would be kindly grateful.