Great to hear you found a solution.

 

Swanolck, I know this is an old thread but I have the same problem. When you replaced the HPOP did you also replace the IPR or just reuse the old one? My HPOP is not very old but im running the OEM IPR.

 

To be honest I don't remember. More than likely if we switched it out, it was a used one. We were switching parts back and forth from all the 7.3's we had here at the time. The HPOP definitely cleared up the hesitation issue we were having though. Is your truck modified? Do you run a tune?

 

Yes:
6637, Zoodad, 6-Pos TS, 203* Thermo, 4" MBRP w/ Aeroturbine, Bellowed Up Pipes, Turbomaster Wastegate, non-EBPV pedestal & outlet, Plenum Inserts, AIH Delete, Intercooler boots, Overboost Annihilator, Wicked Wheel, Stancor Glow Plug Relay, and HXP.

Those are the main ones. And the tuner is currently unplugged.

I have scanned the truck and no codes (other than the pedestal and AIH).
I have swapped out 3 different CPS's and runs the same.
I pulled all 8 injectors (they are rebuilds <10k) had them bench tested and all good. One had a bad o-ring so I replaced all the o-rings.
Watched them run with the VC's off and they all spit oil evenly.
I replaced the ICP because it ran the same unplugged.
UVCH was replaced a couple years ago still looks good and tightly connected.
Cleaned EBPS and tube (read good on scan too).

 

Replaced the HPOP a little less than 2 years ago.

Truck has +188k miles on it.

 

Did you go with the adrenaline HPOP?

 

No its just an OEM spec replacement. I was going to but an adrenaline in but they were out of stock for an unknown time when I needed it and it was my daily driver.

 

Has it been hesitating the whole time? Even when you replaced the HPOP?

 

The truck idles a little rough (most people would say its just a 7.3 but I have driven it for 8 years) then it misses/shakes/shutters real bad in the 1200-1800 RPM range and the worst at 1500. Only in the pedal, as soon as you take it off its normal. And if you run at 2000 RPM it runs strong. The worst is 1500 RPM when it shifts into OD, bad enough to spill a full glas of water. It Feels like when my Valve Cover harness came undone but I checked it all out. And unplugged each injector one at a time while running, each was running the same.

 

No, this all started about 2 months ago. The HPOP has been in the truck for 2 years.

 

Idk. Mine would just have this skipping/hesitation around the same RPM's. Same thing though, let off or get into it and it cleared right up.

We went nuts trying to fix mine. As you can see from the first part of this thread, we tried a lot of different things. It didn't throw any codes or anything.

Do you know any diesel techs that can connect their computer to it when you are driving? That's what we did finally. That's when he said the HPOP. We took the one out of my husbands mason dump and sure enough the problem was solved! Couldn't believe it after all that time...

I drive a 2011 F350 with the 6.7L. OMG I love it. The power is amazing. Plus, I can actually hear the kids talking to me from the back seat. LOL. Of course there are times I really miss rolling the coal and the fact that it cost more than my first house, well we won't go there....

If you have the time and $$ I would try the adrenaline. Good luck!!

 

Yeah we ran a scanner while driving it and I think it was all good. But I can do it again. Thanks for your quick responses and help.

Im getting to the point of giving up on Fords. I have had just about every single thing go in this truck. Last weekend I did the dreaded dipstick at the oil pan repair. That will put some white (skip the gray) hairs on your head.

 

The diesel tech we went to had the laptop so he could watch the pressures in the motor while I was driving. Not just the scanner. We did that too, but it never showed anything.

I understand how you feel. We went through a bunch of 7.3's over time and they each had their own set of problems. I love my fords though.

 

How much did the tech charge you to tell you it was the HPOP?

 

The question is why? What was the root cause? What was wrong with the hpop that caused the low throttle stutter? If no throttle input makes the stutter go away then is the computer determining the fuel requirement? If giving a little more throttle makes the stutter go away then higher fuel pressure fixes the problem? At low throttle input with light demand on the truck, the hpop should be putting out its lowest pressure, right? If this is right then why is it putting out less than required when in this state? Other than a hpop replacement that hopefully does not have the same problem, how do you fix it? How do you test to know? I am new and just trying to understand how things work instead semi random parts swapping that seems to be the prevalent troubleshooting method. The poor guy who started this thread was advised to swap out lots of good parts at great cost without solution.