Ford 6.0L Power Stroke Diesel :: Surges / Buck At Acceleration - Gallop / Miss / Stall At Idle?

I've seen the gods of the diesel engine do some amazing things on these forums, so after a year of pulling my hair out, I've signed up to try this myself.

This time least year,I bought a 2004.5 6.0L F-250 with 196k on it to haul around the state for my new business. At this time, I knew nothing about diesel engines AT ALL WHATSOEVER, but I've never been afraid to tackle anything and mechanics are not totally foreign to me. Not to mention, I was hoping everything might just go peach-ily for at least a couple years. (for what it's worth, My dad and his family are mostly shade tree mechanics and I'm a power plant operator so mechanical concepts are not totally foreign to me, just never had a diesel before)

To begin, I purchased the truck and everything was fine for about 2 weeks. Then abruptly one morning I noticed a couple of hefty surges on the way to work. Then, on the way home I thought all was well until about half way home, it did it again! as I was pulling up, it galloped once I pulled my foot off the pedal. like ba-DA-DA-DA-da-da-da-da-da-da-DA-DA-DA-DA-DA-da-da-__ and then STALL! Shaking with concern over potentially an awful purchase, I turned the truck back on only to find... that it's fine?!?? No problems for the next two days and then it happened again. then good for a week, then again. then good for 2 weeks, then again. so then I bought auto enginuity and an edge insight to do some troubleshooting. Let that sink in as I explain it's history a bit.

-All but one injector is ford remanufactured the other is stock (was never told which one)
-replaced head gasket with another OEM
-ARP Head Studs
-EGR delete
-HPOP AND STC fitting both replaced
-FICM replaced
-Oil cooler replaced 50k ago
-ICP and pig tail replaced right before my purchase
- Has been through roughly a handful of ICP's since I've had it (I'll explain)
-I've cleaned the EBP tube a lot and updated it to the newer ford sensor with the flare fitting

-I use Rotella T6 5W40 and CAT ELC-1 Coolant.
-Deltas are under 10 at normal driving
-I typically drive under 2200 rpm until warm then like a banshee at operating temps.

Now one year later, its not fixed, but I feel like I'm close.

The DTC's I have seen are ICP sensor circuit intermittent (I think po2884) and Power Blance contribution failure from cylinders #2 #7 and #8 but never at the same time.

Every time I replace the ICP, it will be problem free for about 6 weeks and then it will return full force (surging and galloping when warm about 50% of the time)

During a possession I see the following:

*Cylinder power contribution test yields no issues at idle or when cold. when "possessed", the whole baseline across all cylinders goes up and all cylinders dip and return at random. none singled out

*ICP voltage fluctuating from ~.6v to 1v (.24 @koeo) *Also during a surge*

*ICP PSI dancing up and down ~600 to 900psi (0.0 @koeo and ~500 at normal warm idle) *Also during a surge*

*IPR% bumps up and down ~25% to 30% (15%@ koeo and 23% at normal warm idle) *Also during a surge*

*FICM Voltage anywhere between 47.5v and 49v

*EBP is normally 15-20 psi

*Boost is 1-7 normal and is not affected by "possession"

These numbers have taken a long time to get since it will only be possessed for about 3-10 seconds at a time and then will disappear for days. The stall has only happened about 5 total times in a year. The surging is much more frequent. I usually get a buck or 2 on any given trip that is longer than a half hour but NOT IMMEDIATELY AFTER AN ICP REPLACEMENT.

On one occasion, I noticed that the ICP PSI actually tanked to about 350 right before the IPR went from 25% to 40% right before a posession. I was driving about 35mph through town at the time.

Here's my thoughts...

- Did that one occasion clue me in to an intermittent HPO system leak causing the truck to briefly over-compensate by spiking the IPR?

- Is my ICP pig tail jobby done incorrectly? If there was a short, wouldn't I see the volts drop to 0? I have another one and will replace to rule it out.

- I have yet to test my fuel pressure, but I figured if it was low, I would have lost injectors by now. (I replace filters probably too often but next empty tank, I'm dropping it and checking the screen and strainers)

I should also mention that I have buzz tested the injectors and I can hear each one clear as day, and that for REALLY long trips, it actually returns to normal. In other words, my window of death is between 30min and 2hrs of driving; invincible after.