2008 6.4 loosing rail pressure

[JBird08]

Mods:
100% nozzles added to previously replaced 10k mile motorcraft injectors
dual fuelers(Elite kit), both have been replaced in attempt to repair
Return fuel system, elite, regulated to 9.5 psi, monitored and sustained
s476 kit, H&S


Under heavy throttle, injection pressure falls off and vehicle looses power. Fuel pressure maintains and vehicle drives normal under all other circumstances. Any thoughts?

 

[Black AOD]

Good luck with this, I fought this issue on my old 6.4 for a while. How old are your k16s injection pumps? How many miles? K16's were not the greatest pumps ever and were notorious for bad PCV's and the internals wearing quickly due to fuel contamination

 

[JBird08]

Good luck with this, I fought this issue on my old 6.4 for a while. How old are your k16s injection pumps? How many miles? K16's were not the greatest pumps ever and were notorious for bad PCV's and the internals wearing quickly due to fuel contamination

When the problem showed itself, I replaced both pumps with motorcraft rebuilds, same issue instantly

 

[Black AOD]

When the problem showed itself, I replaced both pumps with motorcraft rebuilds, same issue instantly

Motorcraft rebuilds are known for being junk as well.

I would have the pumps and injectors flow tested. If it still occurs, it may be the low pressure system. If it's not that, it may be your PCM failing. That's what mine ended up being although mine was an oddball case.

 

[JBird08]

Motorcraft rebuilds are known for being junk as well.

I would have the pumps and injectors flow tested. If it still occurs, it may be the low pressure system. If it's not that, it may be your PCM failing. That's what mine ended up being although mine was an oddball case.

What was your symptoms?

 

[Black AOD]

What was your symptoms?

Twin pumps and 100% overs with mid sized VGT compounds and no matter what we did it would drop rail in all gears and had serious power loss. We went through my fuel system top to bottom, three times. Replaced every part possible.

Finally on a random whim we tried a new PCM. Fixed everything

Sent from my SM-N950U using Tapatalk

 

[sideactiondiesel]

when has the Pressure sensor been changed in all this? Also what is commanded and actual pressure? also need reg%