Well currently I have the truck at pure diesel getting worked on. I'm wondering if my snap-on scanner is showing me different results while timing the pump. They have a GM tech 2 and a few guys who are old school and have been working on these things for years hopefully they get somewhere on it.Idk. My theory is when you know something isn’t right, fix it and watch the effects. Especially when something is acting goofy.
Yeah this truck is becoming a pain.Hopefully they will finally give you an answer on what the problem is. I know your at wits end with that truck, but I LOVE when I get an "impossible" truck to fix at work. Diagnostic work is my favorite.... but of course I'm not paying for it so I would feel differently if I did.
Judging by what they told you the next step I would do would be to scope the cam/optical and crank sensor. Also id check the alternator for excessive AC ripple. AC voltage can wreak havok on sensor signals.
Id love that but I'm invested already into this DS4Throw a db2 and stand alone trans controller at it and be done if emissions is ok there