Intermittent Fuel Pump
Thread Starter
|
Senior User
Joined: Aug 2006
Posts: 303
Likes: 0
Intermittent Fuel Pump
Hey all,
My fuel pump is not always getting 12v. When it does get 12v the truck runs fine, but when it doesn't, it runs awful. I have a vegistroke kit installed, and it runs great when on veg. Could the #30 relay cause this? By the way, the WTS light always lights up. When the diesel pump is getting 12v the fuel pressure is fine.
When it first started acting up, I immediately thought the tank screen was clogged, but I happened to have it in the shop for something else, and the mechanic said the pump wasn't getting proper voltage all the time.
Are the fuel pump/PCM and the blower motor relays the same? If so, I thought about swapping them to see if that cures it.
Any ideas?
Thanks,
Brad
My fuel pump is not always getting 12v. When it does get 12v the truck runs fine, but when it doesn't, it runs awful. I have a vegistroke kit installed, and it runs great when on veg. Could the #30 relay cause this? By the way, the WTS light always lights up. When the diesel pump is getting 12v the fuel pressure is fine.
When it first started acting up, I immediately thought the tank screen was clogged, but I happened to have it in the shop for something else, and the mechanic said the pump wasn't getting proper voltage all the time.
Are the fuel pump/PCM and the blower motor relays the same? If so, I thought about swapping them to see if that cures it.
Any ideas?
Thanks,
Brad
Senior User
Joined: Mar 2012
Posts: 492
Likes: 0
From: Jenkintown, PA
Here is the fuel pump electrical diagram from 1999 (don't know if there were any major changes from 99 to 01):
Power comes from fuse #19 (20A) through the fuel pump relay and the inertia shut off switch to the fuel pump motor.
Chris
Power comes from fuse #19 (20A) through the fuel pump relay and the inertia shut off switch to the fuel pump motor.
Chris
Thread Starter
|
Senior User
Joined: Aug 2006
Posts: 303
Likes: 0
I'll check the wiring too!
Thanks for the replies!
Brad
Hotshot
Joined: Jan 2011
Posts: 18,849
Likes: 179
From: Puget Sound
Fuses aren't typically intermittent, but it's always a good thing to check. Relays, connectors, and switches are almost always a good source of inttermittent power. I'd start simple with inspecting connector contacts, then I'd inspect relay contacts, then I'd see if I could find those switches and ohm them out. If the problem wasn't intermittent, I'd follow the missing voltage back with a meter.
Senior User
Joined: Mar 2012
Posts: 492
Likes: 0
From: Jenkintown, PA
I don't see a number associated with the relay, but the diagram says it's in the relay block, which I believe is near the instrument panel.
Thread Starter
|
Senior User
Joined: Aug 2006
Posts: 303
Likes: 0
I found the relay block behind the radio. Searchs revealed this is the location for the fuel pump relay. There are a few bigger relays and a small relay. NAPA and the dealer numbers say the smaller relay is the correct relay for a fuel pump. The question is "is it the one for the fuel pump?" The truck started and ran without the relay in! Is that even possible - if so, I would like to know how.
Anyway, I replaced the relay. The truck ran fine most of the day, but decided to act up after switching back from veg last night. I switched back to veg and immediately back to diesel and it ran fine. I'm leaning towards the veg on/off switch is not making good contact when going back to diesel.
The switch is cheap enough that I think I'll throw a new one at it.
Anyway, I replaced the relay. The truck ran fine most of the day, but decided to act up after switching back from veg last night. I switched back to veg and immediately back to diesel and it ran fine. I'm leaning towards the veg on/off switch is not making good contact when going back to diesel.
The switch is cheap enough that I think I'll throw a new one at it.
Trending Topics
Senior User
Joined: Mar 2012
Posts: 492
Likes: 0
From: Jenkintown, PA
How is your veg/diesel system designed? Does the switch control a valve that selects fuel from the desired tank, or does the switch enable an entirely separate fuel pump?
Chris
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Top 10 Ford Truck Tragedies
Joe Kucinski
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Hotshot
Joined: Jan 2011
Posts: 18,849
Likes: 179
From: Puget Sound
Maybe this is old news to others, but I just stumbled onto this today:
"Inertia Fuel Shutoff" Allegedly, if your vehicle gets whacked hard enough - it shuts the fuel off and needs to be reset. I have not yet looked any deeper into this, I'm preoccupied with pulling the trigger on my Buck$Zooka today. I just thought this info was worth mulling over.
"Inertia Fuel Shutoff" Allegedly, if your vehicle gets whacked hard enough - it shuts the fuel off and needs to be reset. I have not yet looked any deeper into this, I'm preoccupied with pulling the trigger on my Buck$Zooka today. I just thought this info was worth mulling over.
Thread Starter
|
Senior User
Joined: Aug 2006
Posts: 303
Likes: 0
The veg system has a separate fuel pump. I'm going to look how many poles are on the switch.
The truck hasn't been in any sort of wreck or even a hard jolt while driving.
Thanks for responding - what did we do before forums?
Ok - gotta ask what is a buckszooka?
The truck hasn't been in any sort of wreck or even a hard jolt while driving.
Thanks for responding - what did we do before forums?
Ok - gotta ask what is a buckszooka?
Thread
Thread Starter
Forum
Replies
Last Post
bigwill250
Explorer, Sport Trac, Mountaineer & Aviator
13
Oct 28, 2006 09:44 PM
JasonStevens
Fuel Injection, Carburetion & Fuel System
3
Oct 3, 2003 11:12 AM