Fuel pump troubleshooting
Thread Starter
|
Freshman User
Joined: Aug 2007
Posts: 45
Likes: 0
Fuel pump troubleshooting
My 2001, F-150 XL, 4.2L, 2WD with 135K miles has left me stranded on a busy highway - again, with a totally different problem. It was over 90 degrees out and I had about 1/8 tank of gas. It just died and acted like it wasn’t getting gas. I put a few gallons more in just to make sure the gauge wasn’t reading wrong.
After being towed home I tried to listen for fuel pump sounds with key in on position and only heard a single short gurgle after a few seconds every time key is moved from off to on. (what is that?) Never heard a whirring sound. I checked the fuse and swapped the relay for the pump and PCM power. There is 12v at the relay and 12v for a few seconds at the connector by the tank going to the fuel pump (I used pink/black & chassis ground).
I read online that you can spray WD-40 into the throttle body air intake and if the engine tries to fire then it is definitely a fuel problem. Is this true? Because it didn’t try to fire.
Then I connected a battery directly to what I think are the fuel pump wires at the tank (a black and a pink/black). I was hoping to hear the whirring sound - no luck.
So my questions are: is the WD-40 a good test because that is throwing me off -- and-- do I have a bad fuel pump? Any help is appreciated!
After being towed home I tried to listen for fuel pump sounds with key in on position and only heard a single short gurgle after a few seconds every time key is moved from off to on. (what is that?) Never heard a whirring sound. I checked the fuse and swapped the relay for the pump and PCM power. There is 12v at the relay and 12v for a few seconds at the connector by the tank going to the fuel pump (I used pink/black & chassis ground).
I read online that you can spray WD-40 into the throttle body air intake and if the engine tries to fire then it is definitely a fuel problem. Is this true? Because it didn’t try to fire.
Then I connected a battery directly to what I think are the fuel pump wires at the tank (a black and a pink/black). I was hoping to hear the whirring sound - no luck.
So my questions are: is the WD-40 a good test because that is throwing me off -- and-- do I have a bad fuel pump? Any help is appreciated!
New User
Joined: Sep 2011
Posts: 2
Likes: 0
NO GAS
Pk/Blk Wire Is Power And Black Is Ground. With Key Turned On You Will Only Have Power For A Couple Of Seconds. With Engine Cranking You Will Have Power All The Time. Also Check For Spark, But It Does Sound Like A Bad Fuel Pump. WD 40 Will Work But Starting Fluid Or Carb Cleaner Is Better To Spray Into Throttle Body, Just A Little Bit Goes Along Way. Also IF Someone Can Crank Engine Or Turn The Key On While You Are Under The Truck, Bang On Bottom Of Tank, Sometimes THe Pump May Run For A Couple Of Seconds.
Thread Starter
|
Freshman User
Joined: Aug 2007
Posts: 45
Likes: 0
It looks like I have no spark, since it didn't try to start when I sprayed the WD-40, and a bad fuel pump. I did try banging on the tank with a short 2x4 but not while the key was being turned. Thanks for the help!
Hotshot
Joined: Jul 2005
Posts: 11,932
Likes: 181
there is a schrader valve on the fuel rail on the motor... looks like a tire valve for air... push the center needle and see if you have fuel squirt out. It should have about 40 psi. You can check when setting, then turn the key on 3-4 times with a few second apart, and see if that builds up pressure.
Thread Starter
|
Freshman User
Joined: Aug 2007
Posts: 45
Likes: 0
Hi Steve,
I forgot to mention above that I had the fuel line apart at the filter (on the gas tank side) and nothing came out when trying to start the truck.
Do you know what the symptoms would be if the gas was contaminated? Would it lock up the fuel pump and maybe clog the fuel injectors too?
Thanks for your input!
I forgot to mention above that I had the fuel line apart at the filter (on the gas tank side) and nothing came out when trying to start the truck.
Do you know what the symptoms would be if the gas was contaminated? Would it lock up the fuel pump and maybe clog the fuel injectors too?
Thanks for your input!
Senior User
Joined: Nov 2008
Posts: 154
Likes: 0
Lenny, I have never had luck with wd-40 as a starting agent. I would dump a teaspoon or so of fuel down before wd-40.
While it is possible for the injectors to get clogged like you say, it sounds to me like your fuel pump is not working. You should have some fuel come out of the line when you take it apart but not alot.
Steve has a great suggestion of turning your key on and off 3 or 4 times and then check the valve he described on the fuel rail.
While it is possible for the injectors to get clogged like you say, it sounds to me like your fuel pump is not working. You should have some fuel come out of the line when you take it apart but not alot.
Steve has a great suggestion of turning your key on and off 3 or 4 times and then check the valve he described on the fuel rail.
Thread Starter
|
Freshman User
Joined: Aug 2007
Posts: 45
Likes: 0
I bought a can of starting fluid and sprayed just a few seconds worth into the throttle body, then got in and turned the key. The truck started right up. I've used WD-40 for starting lawn tractors and such but I guess it doesn't work with fuel injectors.
Thankfully now I'm looking at just the fuel pump problem.
Thinking the fuel pump was bad anyway - I hooked 12 volts up to it backwards, with the hope the pump motor would turn backwards and free itself. No luck. Now I need to get the truck up the hill to a level spot in my crowded garage and hope there is enough room to drop the tank.
Thankfully now I'm looking at just the fuel pump problem.
Thinking the fuel pump was bad anyway - I hooked 12 volts up to it backwards, with the hope the pump motor would turn backwards and free itself. No luck. Now I need to get the truck up the hill to a level spot in my crowded garage and hope there is enough room to drop the tank.
Trending Topics
Thread Starter
|
Freshman User
Joined: Aug 2007
Posts: 45
Likes: 0
Mission accomplished
Just to complete this story -
I attached some eye-bolts to the concrete step in the back of the garage, hooked a 12v winch to a strap between the bolts and pulled the truck into the garage.
Removing the tank was easier than I thought - only 2 bolts holding the two straps. I had problems with the tank pressure sensor connector on top of the tank but finally got it apart. Working with the truck on jack stands in a cramped garage made it challenging to disconnect the two vent line hoses, the filler tube, the overflow tube, two fuel lines and the two electrical connectors. I used a small floor jack and some 2x4 shims to lower and raise the tank to different positions to facilitate the removal. I replaced the vent and over flow tubes (the overflow is slightly bigger which caused some problems because I tried to fit the smaller hose over its fittings) but used the old filler tube because the store didn't have gas rated hose that diameter. There was only about 8 gallons left in the tank so it wasn't all that heavy. I did empty the tank after removal and swish some new gas around in it to clean it out. The empty tank is light enough for one person to handle. (I'll have lawn mower gas for quite a while.)
A Ford dealership wouldn't sell just the pump and was going to charge over $400 for the whole assembly. I didn't even ask how much the labor would be. I bought a Bosch fuel pump for $120 from Advance but had to buy a new strainer for $20 and fuel filter for $12 to validate the one year warranty (probably a good idea anyway).
I put in 5 gallons of new gas and the truck started right up. I'm sure glad to have my own wheels again. But I did get some exercise riding my bicycle to the parts store.
I attached some eye-bolts to the concrete step in the back of the garage, hooked a 12v winch to a strap between the bolts and pulled the truck into the garage.
Removing the tank was easier than I thought - only 2 bolts holding the two straps. I had problems with the tank pressure sensor connector on top of the tank but finally got it apart. Working with the truck on jack stands in a cramped garage made it challenging to disconnect the two vent line hoses, the filler tube, the overflow tube, two fuel lines and the two electrical connectors. I used a small floor jack and some 2x4 shims to lower and raise the tank to different positions to facilitate the removal. I replaced the vent and over flow tubes (the overflow is slightly bigger which caused some problems because I tried to fit the smaller hose over its fittings) but used the old filler tube because the store didn't have gas rated hose that diameter. There was only about 8 gallons left in the tank so it wasn't all that heavy. I did empty the tank after removal and swish some new gas around in it to clean it out. The empty tank is light enough for one person to handle. (I'll have lawn mower gas for quite a while.)
A Ford dealership wouldn't sell just the pump and was going to charge over $400 for the whole assembly. I didn't even ask how much the labor would be. I bought a Bosch fuel pump for $120 from Advance but had to buy a new strainer for $20 and fuel filter for $12 to validate the one year warranty (probably a good idea anyway).
I put in 5 gallons of new gas and the truck started right up. I'm sure glad to have my own wheels again. But I did get some exercise riding my bicycle to the parts store.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
Top 6 Best Deals Available on New Fords & Lincolns Right Now
Brett Foote
This Hennessey Takes the Expedition Tremor's Off-Roading Capability to the Next Level
Verdad Gallardo
Top 10 Fords at 2026 Carlisle Ford Nationals
Joe Kucinski
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
Thread
Thread Starter
Forum
Replies
Last Post
MyBallsHurt
1987 - 1996 F150 & Larger F-Series Trucks
10
May 20, 2018 08:08 PM
shane733
Explorer, Sport Trac, Mountaineer & Aviator
2
Apr 5, 2004 04:21 PM
