Help needed from the cat Gurus

Hello 1johnb / guys-
Not a mechanic as many of you already know, but years ago when the cam had to be replaced in my 2004 MBN C15, I had the local independent tech install the marine cam (part #130-1097 IIRC). Unknown to both the tech and myself, that cam is not compatible with a stock MBN ecm; it idled great, but off of idle it stumbled bad @ 1100 rpm up, and boiled white smoke out the pipes just like your truck. DDS caught the problem and flashed the ecm to a 6NZ, for me, it was "problem solved".
I know your situation is different, but I was told the white smoke coming out my exhaust was raw unburned fuel.
Doubt if this will help you, but throwing it out there just in case. Trying to solve a problem like that can be a real pain........Good Luck

 

Change the cam to stock and problem will go away

 

I have had this same situation with marine cam and stock program.problem goes away with pdi program.

 

I havent had any problems with cam stamped wrong either,so i dont know,but it looks like cam issue to me.do you have access to pdi ecm just to try?

 

It does sound like its starving for fuel or air in fuel system.

 

After watching the videos. I agree with DDS for fuel starvation as one possible cause. But in the first video the truck backfired hard with flame out the stack. I would be very suspect of the cam with this happening. Either the cam was stamped with the wrong part number or the injector lobes were ground with the wrong profile on them. The newer engines can't not tolerate the older design injector cam lobe profiles without a modified file in the ECM to closely match the injection timing of the ECM to the lobe profile. IT looks more like a timing issue than a fuel starvation issue in my opinion

 

If the snubber is gone, you need to look at all the hose and all the fittings from the filter base to the head. It can be lodged in these areas causing a fuel restriction in the fuel rail of the head. Unfortunately you are taking all your fuel pressure readings at the secondary fuel filter base, which is before the cylinder head. You need to install a fuel pressure gauge in the return line after the cylinder head to see if you are having a major fuel restriction to the injectors .

If it was a injection timing issue(cam)..........it should be there all the time, not coming and going in a 25 mile test drive.

Now if it is a fuel starvation issue this will effect injection timing also. How? The injector body isn't 100% filling with fuel and raising the plunger to its max lift. When the cam lobe comes around to push the injector tappet down, the internal pressures don't rise in the injector body properly to raise the needle off the seat of the tip at the proper time. So the injection timing gets screwed up also. If the body isn't full of fuel the injectors pressure rise internally is delayed, hence the needle doesn't raise up from the seat at the proper time. The injector needs the effects of hydraulic pressure internally to lift the needle, which then starts the injection process. Delay the rise in pressure by not filling the injector body completely, you than delay injection timing. I would think this thing is hard to start, but at slow engine speeds the injector may fill and fire properly, but as RPM increases the injector isn't filling 100%