Notices
1999 - 2003 7.3L Power Stroke Diesel  
Sponsored by:
Sponsored by: DP Tuner

Fuel Pressure ?'s

Thread Tools
 
Search this Thread
 
Old Jan 1, 2009 | 10:18 PM
  #1  
97biostroke's Avatar
97biostroke
Thread Starter
|
Senior User
Joined: Nov 2008
Posts: 460
Likes: 0
From: Gifford, IL
Fuel Pressure ?'s

My friends 01 powerstroke with 160k is reading 37 psi at idle. Didnt do a road test, but I would guess it would just dop further under throttle. I know 60-70 psi is a good number to shoot for, but what problems would 37 psi cause, if any? Could it hurt fuel mileage or cause a rough idle? Should we shim the FPR or replace the fuel pump? Or should we just ignore it and let it be? It runs good right now, but it feels like it could run a little bit better.
 
Reply
Old Jan 1, 2009 | 10:52 PM
  #2  
Tenn01PSD350's Avatar
Tenn01PSD350
Post Fiend
Joined: Feb 2006
Posts: 11,892
Likes: 2
From: Middle Tennessee
That is inadequate for your friend's truck. I am surprised it runs even OK. Make sure the filter is good. May want to blow out the line from the pump back into the tank with compressed air. (open fuel fill cap for this) Better yet is to drop the tank and inspect the pickup and screens. Do the in tank mod if you go there. There are also restrictors in the heads where the lines go into the head but I doubt this is the problem. Where did you measure the fuel pressure?

His pump may be on it's way out. How many miles on it? Never mind, saw 160K. It may be time.
 
Reply
Old Jan 1, 2009 | 10:56 PM
  #3  
bdrummonds's Avatar
bdrummonds
Post Fiend
Joined: Sep 2006
Posts: 5,584
Likes: 0
From: Millbrook Alabama
37 #s is real close to the low threshold. I would investigate the fuel pump, and all the fittings from the tank to the fuelbowl. It may be sucking air from the quick disconnect fitting at the tank and not letting the pump build the required pressure.
If the pump is deemed bad then a good replacement pump is the Walbro GSL392, its about $130 and will mount in the stock bracket.
 
Reply
Old Jan 1, 2009 | 11:06 PM
  #4  
97biostroke's Avatar
97biostroke
Thread Starter
|
Senior User
Joined: Nov 2008
Posts: 460
Likes: 0
From: Gifford, IL
He dropped the tank and clean the screens in the pickup pump after running biodiesel with enough glycerin in it to plug up the filter in a couple minutes. I'm not sure where they checked the pressure at ill ask em tomorrow. Ill have them check the quick disconnect and all the fittings. Any way to check the fuel pump and see if its shot?
 
Reply
Old Jan 2, 2009 | 02:16 PM
  #5  
97biostroke's Avatar
97biostroke
Thread Starter
|
Senior User
Joined: Nov 2008
Posts: 460
Likes: 0
From: Gifford, IL
Can i try shimming the fuel pressure regulator with a BB? Or should we go ahead and check for leaks, and if none are found replace the pump?
 
Reply
Old Jan 2, 2009 | 02:22 PM
  #6  
tdpower's Avatar
tdpower
Postmaster
Joined: Dec 2008
Posts: 3,340
Likes: 2
A mechanic at international told me to stretch out the spring a little in the FPR. Make sure you have the proper O rings if you open it up. I have been meaning to rig up a gauge for a while to check mine.
 
Reply
Old Jan 2, 2009 | 02:25 PM
  #7  
97biostroke's Avatar
97biostroke
Thread Starter
|
Senior User
Joined: Nov 2008
Posts: 460
Likes: 0
From: Gifford, IL
So pull out the spring and stretch it? I know on the OBS your supposed to put a small BB in there to compress it, so is it different in the super dutys?
Also, where should i get the right o-rings? Assuming they arent re-usable, would autozone or somewhere like that have them or should i go to a stealership?
 
Reply
Old Jan 2, 2009 | 02:28 PM
  #8  
tdpower's Avatar
tdpower
Postmaster
Joined: Dec 2008
Posts: 3,340
Likes: 2
Yes you have to pull it out and stretch it a little. I've heard of the bb way but either would work.
 
Reply
FTE Stories

Ford Trucks for Ford Truck Enthusiasts

story-0

Top 10 Ford Truck Tragedies

 Joe Kucinski
story-1

AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make

 Brett Foote
story-2

Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!

 Michael S. Palmer
story-3

Ford's 2001 Explorer Sportsman Concept Looks For a New Home

 Verdad Gallardo
story-4

10 Best Ford Truck Engines We Miss the Most!

 Joe Kucinski
story-5

2026 Shelby F-150 Off-Road: Better Than a Raptor R?

 Brett Foote
story-6

2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!

 Michael S. Palmer
story-7

10 Most Surprising 2026 Ford Truck Features!

 Joe Kucinski
story-8

Top 10 Ford Trucks Coming to Mecum Indy 2026

 Brett Foote
story-9

5 Best / 5 Worst Ford Truck Wheels of All Time

 Joe Kucinski
Old Jan 2, 2009 | 02:34 PM
  #9  
97biostroke's Avatar
97biostroke
Thread Starter
|
Senior User
Joined: Nov 2008
Posts: 460
Likes: 0
From: Gifford, IL
I've got instructions on how to do the OBS FPR shimming. Will these work or is the Super Duty's different? I would assume its the same, but I thought it'd be worth the time to check and make sure
 
Reply
Old Jan 2, 2009 | 02:39 PM
  #10  
tdpower's Avatar
tdpower
Postmaster
Joined: Dec 2008
Posts: 3,340
Likes: 2
You would be able to tell pretty quick with a gauge hooked up. You might want to do a search on this site, I'm sure it has been discussed in length. Somebody else might chime in with a good procedure.
 
Reply
Old Jan 2, 2009 | 02:44 PM
  #11  
97biostroke's Avatar
97biostroke
Thread Starter
|
Senior User
Joined: Nov 2008
Posts: 460
Likes: 0
From: Gifford, IL
Alright thanks for all the help. I think we'll try shimming and check the pressure, and if it doesnt change much well replace the pump.
 
Reply
Old Jan 2, 2009 | 04:12 PM
  #12  
bdrummonds's Avatar
bdrummonds
Post Fiend
Joined: Sep 2006
Posts: 5,584
Likes: 0
From: Millbrook Alabama
Shimming is nothing more than a stop gap measure. If the pump is weak then the shim will only tax it more. On the back of the fuel bowl right above the fuelbowl heater plug is a test port. The fitting is pictured below its a -20SAE to 1/8" NPT, it can be found at your local hydraulics store. grab a 100PSI glycerin filled pressure guage from the hydro shop too, and then get you a 1/8th" NPT grease gun hose hook up and test for pressure.

here are some pics. the ones of the mounted fuel pressure guages are just to show what you can do with them.

test port


fitting and hose



guage mounting options


 
Reply
Old Jan 10, 2009 | 09:45 AM
  #13  
PSDLOVER's Avatar
PSDLOVER
Tuned
20 Year Member
Joined: Aug 2003
Posts: 366
Likes: 6
From: Webster, Texas
This is why I will no longer burn Biodiesel until it is more uniformly tested and marketed. I was about halfway into a Bio-only tour of the country this summer with family and Fifth Wheel when all this happened to me in the middle of nowhere Wyoming. It cost me dearly; replacing the pump, #8 injector, and a thorough clean out of the tank and lines. All I can say is don't let this happen in the vicinity of Rock Springs, Wyoming and I will never burn Biodiesel in my truck again.
 
Reply
Old Jan 10, 2009 | 10:09 AM
  #14  
DemonRace6's Avatar
DemonRace6
Hi!
Joined: Sep 2007
Posts: 1,268
Likes: 0
From: Central NJ
I know this has been asked but how is the fuel filter?

What is the wether like there? really cold will make it harder for the bio to flow. I run WVO and use a very large pump to get that thick stuff moving.

Leaks in the lines can hurt your pressure but not this much, you should be able to get it and keep it up near 60psi.
 
Reply




All times are GMT -5. The time now is 07:00 PM.

story-0
Top 10 Ford Truck Tragedies

Slideshow: Top 10 Ford truck tragedies.

By Joe Kucinski | 2026-05-18 19:34:33


VIEW MORE
story-1
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make

And it might be even better than that.

By Brett Foote | 2026-05-18 19:26:42


VIEW MORE
story-2
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!

Slideshow: Does lowering an F-150 Lobo RUIN the ride quality?

By Michael S. Palmer | 2026-05-18 19:20:37


VIEW MORE
story-3
Ford's 2001 Explorer Sportsman Concept Looks For a New Home

Slideshow: Ford's bizarre fishing-themed Explorer concept has resurfaced after spending decades largely forgotten.

By Verdad Gallardo | 2026-05-12 18:07:46


VIEW MORE
story-4
10 Best Ford Truck Engines We Miss the Most!

Slideshow: The 10 best Ford truck engines we miss the most.

By Joe Kucinski | 2026-05-12 13:09:47


VIEW MORE
story-5
2026 Shelby F-150 Off-Road: Better Than a Raptor R?

Slideshow: first look at the 810 hp 2026 Shelby F-150 Off-Road!

By Brett Foote | 2026-05-12 12:50:07


VIEW MORE
story-6
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!

Slideshow: Everything You Need to Know about the 2027 Super Duty Carhartt Package!

By Michael S. Palmer | 2026-05-07 17:51:06


VIEW MORE
story-7
10 Most Surprising 2026 Ford Truck Features!

Slideshow: 10 most surprising Ford truck options/features in 2026.

By Joe Kucinski | 2026-05-05 11:17:22


VIEW MORE
story-8
Top 10 Ford Trucks Coming to Mecum Indy 2026

Slideshow: Here are the top 10 Fords coming to Mecum Indy 2026.

By Brett Foote | 2026-05-04 13:49:49


VIEW MORE
story-9
5 Best / 5 Worst Ford Truck Wheels of All Time

Slideshow: The 5 best and 5 worst Ford truck wheels of all time

By Joe Kucinski | 2026-04-29 16:49:01


VIEW MORE