Fuel Pressure Down Lately - Diesel Truck Forum - TheDieselGarage.com
Thread Details Posted by pstrang, this thread has received 5 replies and been viewed 842 times.

 
LinkBack Thread Tools Display Modes
post #1 of 6 (permalink) Old 10-30-2017, 07:32 PM Thread Starter
Member
 
Join Date: Dec 2008
Location: In my truck.
Posts: 444
Points: 60,424
Thanks: 105
Thanked 47 Times in 44 Posts
Fuel Pressure Down Lately

Lot's of threads about fuel lately. Here's my question:

Fuel pressure normally runs ~ 70 psi in idle after the "blue spring" mod and drops to 55-60 psi at heavy load. Truck "seems" to run fine. But a recent change is ~47 psi in idle, and drops depending on load, even down to 30 psi.

1) Fuel pressure gauge might be faulty (I'm trying to verify this).
2) Don't think it's clogged filters because the pressure is still low at idle.
3) How do the OEM pumps fail? Suddenly dead? Or is there a graceful degradation?
4) The fuel pressure regulator ("blue spring") gone bad? How could I test for this?
5) Fuel filter flow-by pressure leakage?

Other ideas? Troubleshooting ideas?

Thanks for the suggestions!

2005-6L/PSD F-250 Lariat CC/SB/4x4:
- MBRP 4" turbo back, Dieselsite coolant bypass filter, Frantz oil bypass filter, X-monitor, Fluidampr, fuel x-over line, intake elbow, EGR cooler delete, wrapped headers and turbo, ARP studs, OEM gaskets, ported heads and manifolds to match, Hot FICM w/ ID Flash, 08+ tranny pan/filter.
pstrang is offline  
Sponsored Links
Advertisement
 
post #2 of 6 (permalink) Old 11-19-2017, 09:15 PM
Senior Member
 
harry6.0's Avatar
 
Join Date: Dec 2008
Location: Spokane WA. area
Posts: 3,051
Points: 142,039
Thanks: 1,507
Thanked 990 Times in 755 Posts
All great questions and possibilities.......

Harry

Jan 03' built 6.0/F250cc4wd trqsft/SCT-tuned by KEM-Performance/Garrett Powermax vg-turbo/blue spring mod/gauges=egt+boost+fuel+SG2/exhaust/airaid intake/DR 4.5 lift/dual bilsteins/315's/greasable ball joints/powerstop/smittybuilt/kc lights/high idle mod/roll-n-lock/Mobil Delvac1 ESP 5W40 with (Archoil AR9100 in the oil) and (AR6200 in the fuel)
harry6.0 is offline  
post #3 of 6 (permalink) Old 11-19-2017, 09:34 PM
Senior Member
 
harry6.0's Avatar
 
Join Date: Dec 2008
Location: Spokane WA. area
Posts: 3,051
Points: 142,039
Thanks: 1,507
Thanked 990 Times in 755 Posts
Mine reads 72-75psi and drops 5psi under load. Cold weather when fuel thickens can make it go up to near 80psi. That said, if this was a sudden change in fuel pressures, I would change the filters first, if still no change for the better, then I would take the pressure sender for the gauge out of the secondary filter test port and hook up an actual mechanical fuel pressure gauge and see what I have, this will tell you if your pump is weak or you have some type of flow restriction or bleed off-suction issue such as a crack in the tank pickup line.

But since I'm way late to respond to this, I'm thinkin you have probably figured this issue out already.

Harry

Jan 03' built 6.0/F250cc4wd trqsft/SCT-tuned by KEM-Performance/Garrett Powermax vg-turbo/blue spring mod/gauges=egt+boost+fuel+SG2/exhaust/airaid intake/DR 4.5 lift/dual bilsteins/315's/greasable ball joints/powerstop/smittybuilt/kc lights/high idle mod/roll-n-lock/Mobil Delvac1 ESP 5W40 with (Archoil AR9100 in the oil) and (AR6200 in the fuel)
harry6.0 is offline  
post #4 of 6 (permalink) Old 11-23-2017, 11:45 PM Thread Starter
Member
Threadstarter
 
Join Date: Dec 2008
Location: In my truck.
Posts: 444
Points: 60,424
Thanks: 105
Thanked 47 Times in 44 Posts
Quote:
Originally Posted by harry6.0 View Post
All great questions and possibilities.......

Harry
With truck age and milage, I decided to replace fuel pump. Preventative maintenance either way. What a PITA that was in my garage with a crawler. Anyway, that wasn't the problem.

Turned out the fuel pressure regulator plunger gasket failed (see attached picture). Already had a new blue spring kit on order. Easy fix.

2005-6L/PSD F-250 Lariat CC/SB/4x4:
- MBRP 4" turbo back, Dieselsite coolant bypass filter, Frantz oil bypass filter, X-monitor, Fluidampr, fuel x-over line, intake elbow, EGR cooler delete, wrapped headers and turbo, ARP studs, OEM gaskets, ported heads and manifolds to match, Hot FICM w/ ID Flash, 08+ tranny pan/filter.
pstrang is offline  
The Following User Says Thank You to pstrang For this addition to TDG:
harry6.0 (01-31-2018)
post #5 of 6 (permalink) Old 11-25-2017, 11:17 PM
Junior Member
 
Jasong's Avatar
 
Join Date: Feb 2015
Location: Plant City Fl
Posts: 317
Points: 35,601
Thanks: 41
Thanked 26 Times in 25 Posts
Needed the blue spring anyway 👍
Jasong is offline  
post #6 of 6 (permalink) Old 11-26-2017, 01:21 AM Thread Starter
Member
Threadstarter
 
Join Date: Dec 2008
Location: In my truck.
Posts: 444
Points: 60,424
Thanks: 105
Thanked 47 Times in 44 Posts
Quote:
Originally Posted by Jasong View Post
Needed the blue spring anyway ?
Already had it. This is my second one. Can't remember how many years it lasted. But I installed it when they first came out.

2005-6L/PSD F-250 Lariat CC/SB/4x4:
- MBRP 4" turbo back, Dieselsite coolant bypass filter, Frantz oil bypass filter, X-monitor, Fluidampr, fuel x-over line, intake elbow, EGR cooler delete, wrapped headers and turbo, ARP studs, OEM gaskets, ported heads and manifolds to match, Hot FICM w/ ID Flash, 08+ tranny pan/filter.
pstrang is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Diesel Truck Forum - TheDieselGarage.com forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Similar Threads
Thread Thread Starter Forum Replies Last Post
Fuel pressure = oil pressure Cummings24v 5.9L Cummins (1998.5-2002) 3 08-23-2010 03:42 AM
Fuel pressure & rail pressure gauges??? SS1156 5.9L Cummins (2003-2007.5) 9 07-23-2009 07:33 PM
Fuel pressure & overflow valve pressure Deeslfxr 5.9L Cummins (1998.5-2002) 4 01-10-2009 12:35 AM
Setting fuel pressure regulator w/out a fuel pressure gauge hhrecovery 2003-2007 6.0L Power Stroke 17 04-02-2007 03:25 PM
anyone doing fuel pressure or oil pressure skinz0021 General Dodge Discussion 7 08-19-2006 03:42 PM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome