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Discussion Starter #1
cruising along on the highway 60mph or so with about 5psi of boost and the truck laoded doesnt matter if it is a trailor and all in the bed. When I start to go up a hill the truck doesnt down shift and the boost will rise to about 20 and then it will miss. Almost like a throttle positioner lost where it was. It is a very noticealbe loss in speed. Took it to a ford delership and the guys rode in the truck with it loaded and they got to see how it was missing. Had a scannor hooked up during the ride. Nothing showed up so they say that nothing is wrong with the truck.... is any one else having this problem or could help?
 

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What model year? What mods do you have? Tuned?
 

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The dealer should have tested your turbo to make sure the vanes are sweeping. Test, verify,repair.From this side all we can do is guess.
 

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Discussion Starter #5
05 f-350 dually, s&b filter, and banks 4 inch from turbo back with cat and muffler. dealer checked fuel pressure... they didnt mention anything. Why do you think it would be the vanes when the turbo does make good pressure and stays up... just misses like fuel is cutting out. When I drive the truck unloaded you never feel it.
 

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05 f-350 dually, s&b filter, and banks 4 inch from turbo back with cat and muffler. dealer checked fuel pressure... they didnt mention anything. Why do you think it would be the vanes when the turbo does make good pressure and stays up... just misses like fuel is cutting out. When I drive the truck unloaded you never feel it.
Ask the dealer mechanic what the fuel pressure was and how he checked it. There is no sending unit so he would have had to hook up manual gauges (which you did not indicate he did ..... AND also the correct Ford procedure for checking fuel pressure is at WOT). I guess I am saying that it doesn't sound like the fuel pressure was checked.

Since you are tuned, it could easily be fuel delivery issue or possibly something in the high pressure oil system.

The HPO system is hard to pin down sometimes, but the 2005 is prone to HPO leaks - especially from the STC fitting. These sometimes show up first as small leaks at high power (when the HPOP is at the highest discharge pressure).

You really need to have a way to watch the ICP pressures and the IPR duty cycle when driving at load. Maybe he did that during the ride, but maybe not.

Then again, it could be the tuner.
 

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Discussion Starter #7
the truck is not tuned and I am sorry but I dont really know the acronyms... could you explain a little more... your help is much appreciated
 

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Sorry about assuming there is a tuner, a past post of yours mentioned an Edge Evolution..

HPO - High Pressure Oil
HPOP - pump
STC - snap-to-connect fitting on the discharge of the HPOP
ICP - Injection Control Pressure (pressure of the high pressure oil)
IPR - Injection Pressure Regulator (what is used to raise and lower the high pressure oil pressure)
 

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I agree. The dealer has to hook up a guage to see fuel pressure.Test,verify,repair.The turbo may have sticking vanes which could give you too much or not enough air as instructed by the computer.
 

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Discussion Starter #10
Thank you that does clear things up and this is not my truck(ktm250sxf) this is my co-workers.. i have let him use my sign in to address this... so all of my previous post are not related :( i do know that thefuel injection control module and both batteries were recently changed
 

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Sounds like the turbo is acting up. Probably overboosting for the load conditions. If you still have an egr system and its overboosting, then the boost pressure will flow backwards in the egr system causing a pop and miss under load, also can have a dead pedal feel at times. It will also blow out the intake sounding like a pop and misfire. I had this same exact symptom your describing when my original turbo vanes were sticking. If you have a boost gauge, you can watch it drop suddenly at the same time it acts up. Turbo needs cleaning or replaced to fix.

Harry
 
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