Also would a video help understand my problem better? I didn't realize that my explanations were so misunderstood.

video wont hurt.

Have you done the 2000 rpm test?

with engine fully warmed up in park do a couple of quick accel/decels to 2500 rpm, 2-3 times, then slowly accelerate to 2000 rpm as best you can run-up in 100 rpm increments, to next 500 rpm and hold for about 30 sec, then go up another 500 rpm in 100 rpm increments and hold s Once you get to 2000 do same thing on way down back to idle, see if rpm is steady or is it hunting, since you have swapped APPs and PMDs I suspect you have a worn or wearing IP fuel distribution armature plunger .

Do you run any lubricity additives? Try adding 1 qt cheapest you can find SAE-30 non detergent engine oil I buy generic stuff at dollar general or whoever has best price , add 1 QT to a tank fill up thay may help for a while with "sticking plungers/armature that I suspect when cold are sticking a little and when warmed up the clearances of the worn parts are not as tight when cold.

How old is the IP?

Another thought how clean are your grounds, that go to the PCM the one that goes between firewall and block, and also the one on pass side aft intake stud by trans dipstick, have to be spotless, I clean them and keep dielectric grease on them for long term.

Remember these puter controlled trucks have sensors 0-5V, if dirty or loose grounds are present inputs for things like feedback loops to puter can be incorrect, more to the gnds (about 20 gnds for OBS GM trucks) on these trucks (all modern vehicles actually) than just the engine to battery gnds.

If you don't have a factory manual to see them a subscription to AllDataDIY I think $33/yr is invaluable renewal is less but you can print from AD-DIY site all your wiring diags and make your own manual Haynes manuals are junk for the 6.5TD trucks search ebay-amazon etc for a set of factory manuals, no longer in print from Helm Inc (OEM site).

I had to make two separate videos, the first time the truck made me a liar lol. I finally drove the trick enough to get the cel to come on. It's throwing a 35 and 36 code. I had it in diagnostic mode in video is why the lights are flashing.

Just finished a 100 mile drive and my final codes are 34,35,& 36. I noticed 34 is something to do with injection timing. How do I check it and how do I adjust it?

Checked everything discussed, hooked truck to scanner and everything looks good. The desired ip timing and actual are right on. Boost looks good, fuel pressure good, fuel temp good. Only flag is the coolant temp sensor shows 304℉ plugged in or unplugged. Doesn't make a difference on love data but when I unplug it the motor revs up. If I leave the coolant temp unplugged truck will start up and run normal. I have tried 3 different sensors including ac last time. I don't know why the ecm is showing 304℉ but if it's trying to compensate for that would probably cause my problem??? Still throwing 35 & 36 code also. But driving truck everyday now even though everything I'm doing is apparently wrong it's getting me back and forth for now.

Hmm. Could the high temp reading be putting the PCM in limp mode?

hello not to sure but i think these vehicles have two temp sensors....one goes to the gauge and one tells the putter what the ambient temp and tells the putter how much fuel it takes and how long the glow plugs stay on....i used to own a trucking company and yes the grounds are very important... since the putter and some of the sensors work on very low voltage....when i got a new teuck the first thing i did was check all the grounds and added several.... and i never had alternator issues or putter issues...i love the 6.5 if they are running right... and like the member said they are very easy to work on...... and the crank position sensor ,,,,,the plug in might look good but the sensor itself is down by the frt seal and below the oil fill.... and since it is an older truck the previous owners might have spilled oil down the frt of the engine....and oil deteriorates rubber ....and guess what the insulation is rubber... the crank position sensor also controls the timing IP....might want to check that also...