X15 2350 performance issues.

[Kiko]

Hello to all. I am having some trouble with a x15 2350 in an international truck. First off the truck came in as was told that it was in de-rate and would not idle down in cold weather. It was -20 c here so immediately I figured it was gelled fuel or froze up. I added some 911 to the fuel. Checked the water separator and fuel level was to the top of the glass so I figured that was it. Changed both fuel filters and left truck inside overnight. Took it for a drive the next day but under load it had no power. It seemed to be stuttering and I could hear a popping from the engine. When not driving it runs ok. I checked fuel delivery and had a steady 100 psi. Monitored fuel rail pressure and it stayed between 29 and 30000 when loaded up. Did a cylinder cut kit test and passed. Did a fuel injector by performance test and it passed all segments a few times. It did have an active code for crankcase pressure short. Found wiring at the plug was bad so changed the sensor and repaired wiring clearing the code. No change to performance. Truck idles fine. Read on here about the high pressure leak test so performed it and had 11000 psi drop in 60 seconds. Tested the fuel rail relief and had no fuel at all at 29000 psi. I am suspecting an injector but am waiting on a injector plug off cap which should be in my hands next week

A question is, under insite, it says that you can lose up to 21000 psi on the leak test. I read in here that this is a misprint and according to me Rawze that you should not have more than 4000 psi drop. Is this correct.

Also I have noticed that the engine brake is not working. Cruise control does. It says on insite that the switch and the percent is working ok. Could this also be part of the problem. I haven’t taken the top off yet to inspect the rockers or solenoids.

Does anybody have any thoughts on this. When I first checked this all it appeared the engine was stuttering and popping. Now it’s not doing that but appears to not have any power at all. Also can’t seem to make boost. I checked the turbo and pressurized the intake charge system with air and has no leaks. Turbo looks ok.