HPFP?

I cant find any answers that really help on Ford's site or any other site. Has no one had this issue?

 

i heard it takes a while to completely bleed the air out, hopefully dustin or someone will chime in and shed some light to your problem.

 

Ive been bleeding it since thursday though. its like it gains all its air back if it sits over a few hours.

It sits over night and when I turn the key on the FRP monitor on the DD says 0 psi.

I crank it and it fires, runs for 2 seconds then the FRP monitor says 110-120, turn the key off and back on 99, I bleed the system and the whole time it reads 0. I crank it after bleeding it reads 1700, 2200, 2500 and fires over and idles are 5000.

I cant see any fuel leaks at all. Runs perfectly normal after it starts.

 

HPFP is going out an d maybe done for...mine did the same thing.

 

same code same everything? that is what i am concluding as well.

How do you bleed the HP and LP side?

its all on the fuel cooler, the low pressure side has the schrader valve, first turn the key to run, push the schrader valve in. do that 3-4 times for 30 seconds or so each until no air comes out.

high pressure side is the other line on the cooler, after doing the low pressure, loosen the screw and turn the key to run 3-4 times and leave it there for 30 seconds. it will purge the fuel out of there. then on the last time as fuel is coming out tighten the banjo bolt. it should fire and be air free at that point. if not redo it.

Did you remove any of the fuel lines under the valve covers ? Check to make sure that there is no Diesel in your oil. If you are loosing pressure, and cant see a leak perhaps there is something loose or misaligned under there.

I know Ford demands that all rail to injector lines be replaced once removed, in addition to all washers. If none of these lines were touched, I am at a loss.

i did not remove any lines under the valve covers. The only thing I removed was the 2 larger front lines on the HPFP so I could pull the intake runner.

 

How do you bleed the HP and LP side?

 

Did you remove any of the fuel lines under the valve covers ? Check to make sure that there is no Diesel in your oil. If you are loosing pressure, and cant see a leak perhaps there is something loose or misaligned under there.

I know Ford demands that all rail to injector lines be replaced once removed, in addition to all washers. If none of these lines were touched, I am at a loss.

 

I got P0087, which is low fuel rail pressure, when my HPFP went bad. Never had an injector pressure code.

 

I read a thread about yours. I have not seen that code so im not 100% sure it is the hpfp.

I had that code when I took the can off too took slot of bleeding but I got it...have you driven the truck yet? Mine never bled until I took out for a drive

Yeah I have put maybe 50-60 miles on it or more. Like I said once its running it runs perfectly fine. When you say a lot of bleeding how much?

 

I had that code when I took the can off too took slot of bleeding but I got it...have you driven the truck yet? Mine never bled until I took out for a drive

 

What kind of washers did you use on the fuel lines?

 

I used the vitron or v something washers from the dealer, the metal ones with rubber on the inside. I torqued them to 18 ft/lbs like it says to the book. My only other thought is its leaking on the HPFP lines from the LP side. I never took the HP side lines loose or off. Or the washers have some dirt or a nick in them.

 

I got the same P0087 code but I also got the others...they would pop up after cranking, and it dieing.

Keep messing with it....its the HPFP though....mine had a bad seal..allowing the fuel to drain back into the tank and lose prime after it sat for a while.

 

I think that is exactly what mine is doing. Loosing its prime. Though I dont get those other codes. I think that is my best bet. New HPFP. I am really not enjoying pulling this turbo every 3 days to replace a part!

 

when you guys turn the key to run, what does your FRP read on the DD before starting? I noticed mine starts high 100ish then slowly creeps down to 0.

 

gallons it seemed like....it took a good test drive before it worked right...I would rule the pump being bad just yet...anyone know if there is a check valve in the system

 

gallons it seemed like....it took a good test drive before it worked right...I would rule the pump being bad just yet...anyone know if there is a check valve in the system

 

really? gallons from the hp side or the lp side? both?

 

Lp...removed the can to make sure I didn't leave something loose...bled the low side forever...then I left one injection line lose at the head...cranked until I had fuel at the line...torqued the line...cranked and it started...truck was hard starting and ran rough till I went out and actually drove the truck after the first drive out ran fine from then on out I would sassy you have an air leak or youhave a check valve that's not working right

 

removed the fuel filter can? interesting? when i bleed the lp side i push the schrader valve in and bleed that several times, then crack the other line on the cooler for the hp side.

Anyone know where those check valves are? i cant find anything about them.

Injection line at the back of the heads?

sorry for all the questions, you guys use names and i dont know where all of that is. i mean ive had a bunch of it apart just never knew the right names for it. haha

 

That's the part where I don't really know where the check valve is but I'm assuming there had to ne one to keep the fuel from bleeding back to the tank when you shut the truck off and park it

 

if i had to guess its in the hpfp. i wonder if i didnt mess it up when i started the truck and got that code on all the injectors. i thought it was air in the system then so i shut it down and bled again and again starting it 2-3 more times with the same result. it was dumping smoke and everything. then the next day it was fine after i bled it.

id like to think its the washers on the lp lines on the hpfp, i just hate to tear it all the way down and back together to find out its the hpfp and do it all over again.

 

Personally I think if it was the pump you would have low pressure issues not bleeding issued unless the pump is pay of the anti drain back or something

 

Ok I tried something different today.

Instead of trying to start it first I just bled the low pressure side first. A lot of air came out then I tried to start it. It started and ran fine. So somehow I am loosing fuel on the low pressure side. Before when I started it it shoved that air to the high pressure side and I had to bleed both. I think I will start replacing the washer seals on all of the lp side besides the lines at the hpfp.

 

I don't know if you have seen this yet.
http://powerstrokenation.com/forums/showthread.php?t=49201
It looks like the only check valve is in the tank which would make sense in a way.
I never studied it too much but maybe it will help you figure it out.
Good luck.

 

Thank you!!! That helps me understand it so much better

 

Theres a seal inside the HPFP that if its leaking it will allow the fuel to run back.

 

I'm trying to leave that as last resort haha

 

What is your fuel level when this is happening???

I have been replaceing alot of faulty fuel senders on 08+ 6.4's dues to them reading incorrectly, the gauge may read 1/8 to 1/4 tank but in reality your dam near empty so you suck up air and it gets into the hp fuel system and causes (most commonly) P0087, P0088, and P2291. Not saying this is your problem, just a possibility.

Also, after you bleed the LP side and its free of air and you move onto the HP side, after you have cycled the key a few times for 20-30 sec, start the truck and let it RUN with the HP line still disconnected untill it is flowing a steady stream of fuel thats free of air. however unless you have the bleed tool from ford you will not remove 100% of the air from the HP fuel system, the rest will have to work itself out on the test drive.

And typically (not always) when a HPFP is going out, once you drive the truck for a few miles and get things warmed up, it fill fall on its face if you try to accelerate past 1/2 throttle and run just fine under 1/2 throttle.

 

it hasnt been below a half tank since i pulled the cab

i tired to let it run with that line disconnected, ha, that didnt work out too well without that tool. what a mess.

mine does not fall on its face at full or any part of throttle, its too busy spinning the tires and throwing me back in the seat.

 

well that proved out not to work, it wouldnt run after sitting 8 hours at work. so im back to square one. ha this diesel diagnostics stuff sucks.

I would really like to take it in and have someone else look over it. I am probably missing something really silly.

 

Seal in the HPFP.......

Oh I said that already...I apologize

 

ha yeah, its about all i have left! i havent been trying to ignore you. i just hate for it to be that.

you said you took the 2 low pressure lines-return off at the hpfp right? those fittings at the hpfp are bad about backing out when you take the fuel line caps loose. your supposed to use a back up wrench but they are hard to get to. if these are loose and not torqued back into the pump right, you will get air in the fuel system, just you are describing.

really? i was unaware. could very well be that. guess its time to pull the cab. i am about ready to anyway and replace all the seals. trouble is if i do all of that i may as well replace the pump. agree?