Oil field truck bought in Longview Texas.

You need to check your battery cables and ground connections on the frame. Bad or corroded connections can cause some weird problems.

 

Is this something that came out with DDEC VI ?
The DDEC V is not fuel cooled.

 

I thought they all were? I'm positive I've seen a few early DDEC I and II with them.

Even this fuel system schematic shows it.

Edit: Didn't see the footnote. Looks like it was removed from certain on-road engines. Not sure how OP would have had diesel in the ECM if there wasn't a cooler on theirs.

 

Gotcha.
I was wondering because my DDEC V road engine isn’t but I have no experience with the DDEC VI.
With all the big changes and emissions crap on the VI
I thought it could be plausible that it might fuel cooled.

 

Sounds like it may have been a Cudd truck or Gemini (Love's) crude truck.

As far as the electrical issue you're experiencing, I'm afraid I can't be much help except to check to make sure that all the connections are tight and free of corrosion. And even though you replaced it, check to make sure your throttle position sensor is showing the correct voltage to the ECM.

 

With only 106,000 miles, how many hours on the engine?

 

Even for an oilfield truck?

@Nickstar I thought of another company that truck might have come from: C&J Energy Services, the coil tubing outfit.