Fuel pump not working

Tiny
KEN
  • ADMIN
Hello,

Here is the fuel pump wiring diagrams with the engine wiring with a guide to help you test it:

https://www.2carpros.com/articles/how-to-check-wiring

Check out the diagrams (below). Please let us know if you need anything else to get the problem fixed.

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Friday, May 29th, 2020 AT 11:40 AM (Merged)
Tiny
GENE RICKS
  • MEMBER
  • 1992 FORD F-150
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 180,000 MILES
I bought truck for a friend 4 mo. Ago. Was running fine. Started it regularly. 6 weeks ago started loping at idle. Friend backed out on deal last week. Had bad fuel. Would not run. Emptied tank, checked pump, changed primary filter, Idle air sensor, Sp. Plugs. Runs butlopes when idling. No vacuum problem. Need advice. Have mechanical experience on Carb's but little on fuel inj. Could it be EGR related or is there another idle controller/sensor I don't know about? Thanks!
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Friday, May 29th, 2020 AT 11:40 AM (Merged)
Tiny
RACEFAN966
  • EXPERT
OK there is only one fuel filter on this on this truck there is no primary or secondary. You did change the filter that looks like a large can right? Now what I would like you to do is get some throttle body cleaner and lean the throttle body out really good. Let me know how it works. You will need a digital multi meter to do some test from here.

Fuel Filter.


https://www.2carpros.com/forum/automotive_pictures/249564_5_1.jpg

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Friday, May 29th, 2020 AT 11:40 AM (Merged)
Tiny
IVAN AZCUE
  • MEMBER
Thanks Ken.

So the inertia switch does need 12 volts at all three wires? One coming from fuel pump relay, another one 12 volts goes to fuel pump one goes to cluster?

If so I do get 12 at both power wires for a couple seconds as I crank engine over then they drop. To 6 volts. The third wire has 12 volts constant (goes to cluster).

It dropping to 6 volts after cranking means? Short to ground or is the switch working properly?
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Friday, May 29th, 2020 AT 11:40 AM (Merged)
Tiny
GENE RICKS
  • MEMBER
Do you mean pull the throttle body and soak in throttle body cleaner or is this a spray cleaner you use while the engine is running?
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Friday, May 29th, 2020 AT 11:40 AM (Merged)
Tiny
KEN
  • ADMIN
Does the system drop to 6 because of a weak battery or just that circuit? Power goes to the switch and the cluster. Can you please shoot a quick video with your phone so we can see what's going on? That would be great. You can upload it here with your response.
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Friday, May 29th, 2020 AT 11:40 AM (Merged)
Tiny
RACEFAN966
  • EXPERT
Ok get some throttle body cleaner and rags. Put a couple of rags below the throttle body and first with the throttle closed spray it out. Now open it and spray it down some more and use another rag to wipe it out real good. Now you can go ahead and start it and see how it runs.
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Friday, May 29th, 2020 AT 11:40 AM (Merged)
Tiny
IVAN AZCUE
  • MEMBER
Thanks Ken, got the rear fuel pump to run. The front ones bad I think there was a loose wire.

Also noticed my neutral safety switch wired to connector were bad.(Rotted) that might be causing my no click no start. I bypassed the relay solenoid on the fender and it starts.

That's my next project. Thanks again
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Friday, May 29th, 2020 AT 11:40 AM (Merged)
Tiny
KEN
  • ADMIN
Nice work, we are here to help, please use 2CarPros anytime.
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Friday, May 29th, 2020 AT 11:40 AM (Merged)
Tiny
SCB0317
  • MEMBER
  • 1991 FORD F-150
1991 Ford F150 6 cyl Two Wheel Drive Manual

the fuel pumps keep running and engine will not turn over
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Friday, May 29th, 2020 AT 11:41 AM (Merged)
Tiny
JACOBANDNICKOLAS
  • EXPERT
What I need you to do is check the fuel pump pressure to the fuel rail. If the pump keeps running, chances are something has come apart on the tank. Here is a how to for checking the pressure.

https://www.2carpros.com/how_to/how_to_check_fuel_pressure.htm

Let me know what you find.

Joe
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Friday, May 29th, 2020 AT 11:41 AM (Merged)
Tiny
SCB0317
  • MEMBER
Tried the fuel pressure test it was 55 have replaced fuel filter, relay, and regulator please help
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Friday, May 29th, 2020 AT 11:41 AM (Merged)
Tiny
JACOBANDNICKOLAS
  • EXPERT
Okay, I'll do my best to help you get it running. Just bear with me asking questions because I'm not there to check things myself. Will the vehicle start with starting fluid? When you say, "It won't turn over, " do you mean the starter isn't working or it does but the engine won't start? I have to ask because everyone has a different way of saying the starter doesn't work or it cranks but won't start.

Let me know.

Joe

PS: It's 10:27PM eastern time. I'll be check my email within the next hour. I look forward to your reply if you are on line.
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Friday, May 29th, 2020 AT 11:41 AM (Merged)
Tiny
SCB0317
  • MEMBER
Yes the truck will start with starting fluid but the pumps keep running and if you give it gas it chokes out thank you so much
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Friday, May 29th, 2020 AT 11:41 AM (Merged)
Tiny
JACOBANDNICKOLAS
  • EXPERT
You have good fuel pressre and it starts with starting fluid, so that tells me you are getting spark which is good. The fuel pressure is good, so the only thing left is the fuel injector. You need to check to see if the fuel injector is getting power. Something tells me that is where the problem is. THree of the injectors will have a tan wire and three will have a white wire on the supply side. On the other end of the injector will be a red wire at all 6 cylenders. WHat I need you to do is using a noid light (ask to borrow at a parts store) check for power to all of the wires I described. You will not get a solid light indicating constant power, but rather you should see a pulsing light each time the injector is told to inject fuel to the cylender. A noid light is simply a small incandescent bulb in a socket with pins that plug directly into the wiring harness leading to your fuel injectors. Crank the engine over. If the noid light flashes, the computer is operational enough to send voltage to the injector.

Here is a picture of one connected to an injector plug:


https://www.2carpros.com/forum/automotive_pictures/249084_noid_1.jpg



This sounds harder to do than it is. If you got through checking fuel pressure, you shouldn't have any trouble with this. Something tells me that the light won't light up for you. If you can't get your hands on a noid light, you could use a test light or volt meter, but it is going to be a lot harder.

Let me know what you find. If there is no pulse to the injectors, then we have to start working backwards to problem solve. It can take some time, but eventually, we'll get it. If you knew me, you now understand why I'm starting to loose my hair (LOL).

Joe
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Friday, May 29th, 2020 AT 11:41 AM (Merged)
Tiny
PKNUPSNIPS
  • MEMBER
  • 1990 FORD F-150
Electrical problem V8 Two Wheel Drive Automatic 120000 miles

My f 150 wont start. It has spark at the plugs. Fuel isn't getting to the fuel rails. The truck has two fuel tanks and I tried to start it using both tanks. It wont start with either tank. I replaced the fuel filter on the frame rail. I don't think its possible for both of the fuel pumps to go bad at the same time. Why isn't it getting fuel?

No I don't here the fuel pumps they are in the fuel tanks. I do here a relay click once right after I turn the key on.
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Friday, May 29th, 2020 AT 11:41 AM (Merged)
Tiny
KEN
  • ADMIN
Hello,

Those trucks had a big problem with the switch valve down on the frame rail between the tanks. Here is a diagram (below) of what the valve looks like.

Please let us know if you need anything else to get the problem fixed.

Cheers, Ken
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Friday, May 29th, 2020 AT 11:41 AM (Merged)

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