Fuel Pump?
Thread Starter
|
Senior User
Joined: Feb 2000
Posts: 110
Likes: 0
Fuel Pump?
Hey guys-
I have a 94 F-150 with a 5.0. My problem is that when I go to start the vehicle, the engine cranks for a long time before firing. It nevers used to do this. My question is, is it the fuel pump or the regulator? I tried searching the archives for this, but could not find a satisfactory answer. Any help would be appreciated.
Thanks-
Doug
I have a 94 F-150 with a 5.0. My problem is that when I go to start the vehicle, the engine cranks for a long time before firing. It nevers used to do this. My question is, is it the fuel pump or the regulator? I tried searching the archives for this, but could not find a satisfactory answer. Any help would be appreciated.
Thanks-
Doug
Senior User
Joined: Jul 2001
Posts: 250
Likes: 1
Fuel Pump?
You are losing fuel pressure, the system is supposed to hold pressure after the fuel pump is shut off. It could be from leaky injectors or I believe there is a check valve in the fuel pump that holds pressure on the system when it is off. Youre regulator could have a weak spring and not closing after the engine is killed.
John
John
Postmaster
Joined: Jul 1999
Posts: 3,172
Likes: 4
Fuel Pump?
Fiddy , You need to have a fuel pressure gauge hooked to the fuel rail to do an accurate diagnosis , otherwise you will just end up taking stabs in the dark . With the KOEO the fuel psi should be 35 to 45 psi , the pressure should go from 0 to 45 psi as soon as the key is turned to run . Shut the key off & note the time , measure what the fuel pressure is 30 mins later . Next start the engine & note its fuel psi , it should be 30 to 40 psi . Remove the vacuum line to the fuel pressure regulator & the psi should go to 45 psi . Let us know what you find . Also , If the fuel filter hasnt been replaced in the last 30K miles that would be a good place to begin & see if the same problem exists .
Thread Starter
|
Senior User
Joined: Feb 2000
Posts: 110
Likes: 0
Fuel Pump?
Thanks Paul - I'll do that this weekend and let you know what I find.
Thans again-
Doug
Thans again-
Doug
Trending Topics
Elder User
Joined: Feb 2000
Posts: 601
Likes: 1
From: South Sioux City, NE USA
Fuel Pump?
Here is a link to some very good info on Fuel Injection and fuel pumps. Give it a read and see if it helps.
[http://www.autosite.com/garage/encyclop/ency07a.asp]
Roger
[http://www.autosite.com/garage/encyclop/ency07a.asp]
Roger
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
3 Best / 3 Worst Parts of Modern Ford Ownership
Brett Foote
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches
Pouria Savadkouei
Every 2026 Ford Engine Explained
Brett Foote
10 Ugly Ford Trucks That We Still Kinda Love
Joe Kucinski
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote