Need Help Dying Low Pressure Fuel Pump?

Powerstroke Man 6.4 · May 11, 2015

Truck is 08 job 3 F-250 270,000 miles billet S366 NL CAI all normal deletes GH tuned.

about a week ago truck started to lope at idle when first started in the morning (70 F) then return back to steady idle within 2 seconds so didn't really pay much attention to the loping idle at first morning start up.

Fast forward a week later now.

Truck was running fine yesterday then today pulling from a stop light at light throttle TC locked lost power (dead pedal) and regained power (I wasn't paying attention to RP) within a half a second (Full tank of fuel) now the truck will idle higher than normal (800-825) normal (725-750).

Checked for codes with the DD and AE no codes oil level is full no fuel smell coolant is full,no weird noises,no excessive blow by checked upper fuel bowl fuel is clean and no water.

Drove it home thought the tune went corrupt return back to stock idled normal turned it off and reloaded the GH tune let it cool down started it back up idling at normal idle rpm (700-725). I test drove it down the road and stopped on the side to check the idle (still idling norma)l then I did a WOT run and back to high idle (800-825).

Checked injector short term fuel trims they are normal.

Starts up normal

RP at idle is 5000-5100 (Gearhead Race SCT)

A few days ago I logged a WOT run 24664 at 1.808 PW seem a bit low?

Power balance is perfect.

No abnormal PIDS.

EGTS are 1300 WOT

No P0088 or P0087

I do hear a slight whining noise coming from the LPFP on the rail.

I'm going to get a fuel pressure gauge tomorrow and check FP at idle and WOT.

I read that at the fuel cooler the pressure should be 3-8 PSI?

Thanks in advance

Jmoore1225 · May 11, 2015

Are your EGTs a lil higher than normal when driving, cruising?

madman1234509 · May 11, 2015

Negative on the rail pressure
I believe the standard that gearhead commands is 24600. I'm like 90% sure on that.

madman1234509 · May 11, 2015

Stock fuel pump? The manual says at the fuel bowls it's like 2-3psi. They don't run much pressure at all. Check your pressure. There is also a way to test the pump, checking for resistance eletrically. Maybe someone will come in on the specifics. May even be able to search testing low pressure fuel pump or something.

Powerstroke Man 6.4 · May 11, 2015

Jmoore1225 said:
Are your EGTs a lil higher than normal when driving, cruising?

60 MPH the egts are around 750-800 crusing.

35's 3.55's and the S366.

Powerstroke Man 6.4 · May 11, 2015

madman1234509 said:
Stock fuel pump? The manual says at the fuel bowls it's like 2-3psi. They don't run much pressure at all. Check your pressure. There is also a way to test the pump, checking for resistance eletrically. Maybe someone will come in on the specifics. May even be able to search testing low pressure fuel pump or something.

Yes stock LPFP should I test pressure at the Schrader valve or at the fuel bowl?

Powerstroke Man 6.4 · May 11, 2015

Also what could cause the truck to bump its idle up (50-75 RPM) only after a WOT run? Assuming that LPFP pressure is OK oil and coolant,trans,egts etc are normal could high fuel temp bump the idle up?

Thanks for the help I really appreciate it.

Jmoore1225 · May 11, 2015

Powerstroke Man 6.4 said:
60 MPH the egts are around 750-800 crusing.

35's 3.55's and the S366.

Is that typical for your set-up, or have they increased?

Powerstroke Man 6.4 · May 11, 2015

Jmoore1225 said:
Is that typical for your set-up, or have they increased?

They were higher before with PIP tunes 950-1000 at 60 could a dying LPFP cause the higher than normal egts?

(all IC boots are tight/new no rips or tears up pipes are good no leaks.)

Thanks

Jmoore1225 · May 11, 2015

Thats what I'm trying to figure out, everything on my truck is new except the LPFP. Just started getting some EGT temps that have been higher than what they had been since getting the truck backabot 10 months ago. MIne at 70 cruise are still in the high 5's low 600's when flat. 71/59's.

Powerstroke Man 6.4 · May 11, 2015

This is a log at first start up when cold.

I noticed when put in to drive/gear it will have a small lope then with smooth out no matter hot or cold.

(I cant seem to get the real DD log uploaded so it copied and pasted)

RP RPM

0 158.000000
2419 158.000000
2419 158.000000
2419 158.000000
2419 158.000000
2419 158.000000
2419 158.000000
2419 158.000000
2419 158.000000
2419 158.000000
2419 158.000000
2419 158.000000
2419 158.000000
2419 158.000000
2419 158.000000
2419 763.000000
9213 763.000000
9213 763.000000
9213 763.000000
9213 763.000000
9213 763.000000
9213 763.000000
9213 763.000000
9213 763.000000
9213 763.000000
9213 763.000000
9213 763.000000
9213 763.000000
9213 763.000000
9213 763.000000
9213 821.000000
6662 821.000000
6662 821.000000
6662 821.000000
6662 821.000000
6662 821.000000
6662 821.000000
6662 821.000000
6662 821.000000
6662 821.000000
6662 821.000000
6662 821.000000
6662 821.000000
6662 821.000000
6662 821.000000
6662 759.000000
5086 759.000000
5086 759.000000
5086 759.000000
5086 759.000000
5086 759.000000
5086 759.000000
5086 759.000000
5086 759.000000
5086 759.000000
5086 759.000000
5086 759.000000
5086 759.000000
5086 759.000000
5086 759.000000
5086 739.000000
5056 739.000000
5056 739.000000
5056 739.000000
5056 739.000000
5056 739.000000
5056 739.000000
5056 739.000000
5056 739.000000
5056 739.000000
5056 739.000000
5056 739.000000
5056 739.000000
5056 739.000000
5056 739.000000
5056 728.000000
5055 728.000000
5055 728.000000
5055 728.000000
5055 728.000000
5055 728.000000
5055 728.000000
5055 728.000000
5055 728.000000
5055 728.000000
5055 728.000000
5055 728.000000
5055 728.000000
5055 728.000000
5055 728.000000
5055 736.000000
5089 736.000000
5089 736.000000
5089 736.000000
5089 736.000000
5089 736.000000
5089 736.000000
5089 736.000000
5089 736.000000
5089 736.000000
5089 736.000000
5089 736.000000
5089 736.000000
5089 736.000000
5089 736.000000
5089 724.000000
5010 724.000000
5010 724.000000
5010 724.000000
5010 724.000000
5010 724.000000
5010 724.000000
5010 724.000000
5010 724.000000
5010 724.000000
5010 724.000000
5010 724.000000
5010 724.000000
5010 724.000000
5010 724.000000
5010 729.000000
5091 729.000000
5091 729.000000
5091 729.000000
5091 729.000000
5091 729.000000
5091 729.000000
5091 729.000000
5091 729.000000
5091 729.000000
5091 729.000000
5091 729.000000
5091 729.000000
5091 729.000000
5091 729.000000
5091 727.000000
5056 727.000000
5056 727.000000
5056 727.000000

Powerstroke Man 6.4 · May 11, 2015

full DD log in zip.

Powerstroke Man 6.4 · May 29, 2015

Put a gauge on it was making good pressure but it finally gave out last week.

I ordered a new LPFP from dieselfiltersonline should be here tomorrow.

If your factory LPFP ever gives out or making low pressure you can purchase the pump itself from the link below instead of buying the whole HFCM from Alliant or Ford.

http://www.dieselfiltersonline.com/...embly_replacement_pump_kit_f_series_6_4l.html

DWhite · May 30, 2015

Where did you end up testing it and what was the readings?

Powerstroke Man 6.4 · May 31, 2015

DWhite said:
Where did you end up testing it and what was the readings?

At the schrader valve on the fuel cooler iirc it was 3 psi at idle and 2.5 at WOT.

B585Ford · May 31, 2015

Powerstroke Man 6.4 said:
Put a gauge on it was making good pressure but it finally gave out last week.

I ordered a new LPFP from dieselfiltersonline should be here tomorrow.

If your factory LPFP ever gives out or making low pressure you can purchase the pump itself from the link below instead of buying the whole HFCM from Alliant or Ford.

http://www.dieselfiltersonline.com/...embly_replacement_pump_kit_f_series_6_4l.html

When you say it gave out, what exactly did it do? One time I lost my ground on the LPFP and am curious if you experienced the same symptoms.

Powerstroke Man 6.4 · May 31, 2015

B585Ford said:
When you say it gave out, what exactly did it do? One time I lost my ground on the LPFP and am curious if you experienced the same symptoms.

I noticed the truck starting dropping RP the day before the next day jumped in the truck turned the key on and the pump started to make some whine noises hooked up the gauge again no pressure at all and a no start. I turned the key on again no noises at all and no pressure command it on with AE and nothing has 269,000 miles on the truck and i'm pretty sure that was the original LPFP.

Powerstroke Man 6.4 · Jun 4, 2015

Finally got the new pump in.

power is back and it doesn't fall on its face on the top end anymore ,were making good pressure.

B585Ford · Jun 4, 2015

Good deal. Is that the original HPFP?

Powerstroke Man 6.4 · Jun 4, 2015

B585Ford said:
Good deal. Is that the original HPFP?

Most likely yes idk for sure though.

short term fuel trims are 1-2 off from each other on every cylinder and holds max commanded RP on my custom GH Race tune.

better then my 80,000 dually #4 is at +0.13 at warm idle and 0.19+ at cold idle LOL.