jQuery not supported.



Fuel Pump vs Fuel Pressure Reg

Fuel Pump vs Fuel Pressure Reg

Postby CanisHorribilis [OP] » Apr 01 2021, 4:32pm

Hello All,

I am new to the forum. I have been experiencing an issue with my 2001 4.8L with 212000. Intermittent misfire at lower RPMs, sometimes sluggish off the start after engine warm. Idles normally. No issue with initial start, only after driving a bit. Checked Fuel pressure and it is consistant at 45psi. Engine appears to run normally at high RPMs with good power. I have owned it for a year and not too familiar with its service history. Engine normally runs strong, no oil burning and nice idle.

Did not run a diagnostic, yet. Not convenient at moment. Are these the symptoms of a failing pump or pressure reg? Thanks in advance for any help.

Brent
Original Poster
CanisHorribilis
Newbie
Newbie
Posts: 3
Topics: 1
Joined: Apr 01 2021, 4:09pm
Location: Maryland
Year: 2001
Make/Model: Chevrolet Silverado
Group Membership:
Registered users

Re: Fuel Pump vs Fuel Pressure Reg

Postby chevron » Apr 01 2021, 7:28pm

Just throwing out ideas, MAF sensor dirty? Throttle body needs cleaning?
chevron
Firing on 4 cylinders [L1]
Firing on 4 cylinders [L1]
Posts: 45
Images: 0
Joined: Dec 08 2020, 6:41pm
Location: WA
Year: 2015
Make/Model: Chevrolet Silverado
Variant: LTZ
Extra Info: CC Stb 6.2L 4X4
Group Membership:
Registered users

Re: Fuel Pump vs Fuel Pressure Reg

Postby Walkers » Apr 01 2021, 10:21pm

Its he pump. Your pressure is too low. Replace it.
Walkers
Shifting into Sixth Gear! [L3]
Shifting into Sixth Gear! [L3]
Posts: 2990
Topics: 67
Joined: Sep 01 2017, 12:06am
Years of membership: 3 years of membership3 years of membership3 years of membership
Year: 2013
Make/Model: Chevrolet Silverado
Extra Info: Ext cab 2500 4x4
Group Membership:
Registered users

Re: Fuel Pump vs Fuel Pressure Reg

Postby CanisHorribilis [OP] » Apr 08 2021, 1:01am

Thank you for the tips. I replaced the pump (Delphi), filter and Pressure regulator. The issue remains. 45 psi, engine rough at lower rpms. Idles a little rough. Code reader shows P0171. Did note, with the vacuum line off the pressure regulator, the idle improved and pressure went up to 55psi. Can this be vacuum related?
Original Poster
CanisHorribilis
Newbie
Newbie
Posts: 3
Topics: 1
Joined: Apr 01 2021, 4:09pm
Location: Maryland
Year: 2001
Make/Model: Chevrolet Silverado
Group Membership:
Registered users

Re: Fuel Pump vs Fuel Pressure Reg

Postby badbruin44 » Apr 08 2021, 2:51am

I would think it is vacuum related and fuel pressure it should be right around 55 PSI. You might be close to the culprit as you said the pressure returns to normal fooling around with hose.
[gallery][/gallery]
User avatar
badbruin44
Shifting into Third Gear [L3]
Shifting into Third Gear [L3]
Posts: 1321
Topics: 28
Images: 1
Joined: Jan 12 2013, 9:04pm
Years of membership: 8 years of membership8 years of membership8 years of membership8 years of membership8 years of membership8 years of membership8 years of membership8 years of membership
Location: sk ca
Year: 2008
Make/Model: Chevrolet Silverado
Extra Info: 2500 6.0L CAI Gibson
Group Membership:
Registered users

Return to Vortec 4800 4.8L V8

 

  • Similar topics
    Replies
    Views
    Last post

Common search terms

fuel issue engine pump pressure might body driving start high year think thanks help right nice power

It is currently Apr 13 2021, 3:09pm

  • Sponsor
Login  •  Register
Vortec 4800 4.8L V8 Forum
Vortec 4800 4.8L V8 specific.
To create a new topic in Vortec 4800 4.8L V8, click this button:
Previous topic Next topic
Sitewide News Sitemaps & Feeds

Who is online

Users browsing this forum: No registered users and 9 guests