Fuel pump relay?

Tiny
CJC
  • MEMBER
  • 2002 FORD RANGER
  • 6 CYL
  • 4WD
  • AUTOMATIC
  • 110,000 MILES
I have a 2002 Ford Ranger with a V6 4.0L engine. Periodically in cold weather, it will not start. After having this occur several times, I began to listen for the fuel pump to energize before starting. If I didn't hear it energize, it wouldn't start. After turning the key on an off several times(but not turning the engine over), it will energize the fuel pump and then it starts. This only seems to happen in cold weather. Last winter, a mechanic swapped a couple of the relays around and it worked fine. But we never really had much cold weather after that and it started without any problems all spring, summer and fall. Now that winter is here the problem is back. Any ideas on what the problem could be? Thanks.
Saturday, December 4th, 2010 AT 3:50 PM

23 Replies

Tiny
MERLIN2021
  • MECHANIC
  • 17,250 POSTS
It could be either a bad electrical fuel pump relay, or the pump is on the way out. These guides can help us see what's going on with the relay (50b) location below.

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

and

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Check out the diagrams (Below). Please let us know what you find. We are interested to see what it is.
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Saturday, December 4th, 2010 AT 4:39 PM
Tiny
ARL0
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  • 1 POST
Ok I have the same problem. At first it would only happen when I filled the tank up all the way. I thought it would have been a fuel pump relay going bad so I switched it around and got a new one and it still did not fix the problem.

I'm thinking about replacing the fuel pump cause I have no idea what it is so any idea would help me thx.
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Friday, December 24th, 2010 AT 7:10 PM
Tiny
PK1948
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  • 1 POST
This is my third winter with this problem. I have narrowed it down to this. 1. Fuel pump connection (doubtful). 2. Key switch (maybe). 3. Anti theft module (quite likely). I think it could be the anti theft module because it's only when I try to start it. Once it's running, it works flawlessly. And it requires a second relay to pull in when starting. After it's running, I think the fuel pump relay seals around that AT relay. I have bypassed the fp relay and still have the problem but I hear a secondary relay pull in. To eliminate the fuel pump from the mix, I plan to put an electric heater (with fan) under the gas tank and heat the gas up a bit. Here's the print
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Thursday, February 23rd, 2012 AT 3:50 AM
Tiny
WINSTON1
  • MEMBER
  • 2 POSTS
  • 2001 FORD RANGER
  • 6 CYL
  • 4WD
  • AUTOMATIC
  • 64,000 MILES
I have a 2001 Ford Ranger with 3.0 V6. It has a cold weather starting problem. When the ambient temperature is around freezing or below, the fuel pump does not come on when the switch is turned on. When the ambient temperature warms up, then you can hear the pump come on and it will start. After it starts, it runs fine with no problems. Have swapped relays around and hasn't helped. By the time we can get it up on a hoist to check voltage at the pump, it has warmed up enough that it starts. Any suggestions?
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Tuesday, November 24th, 2020 AT 7:41 AM (Merged)
Tiny
WINSTON1
  • MEMBER
  • 2 POSTS
After spending considerable time at the shop, the tech finally hit the situation where there was voltage at the pump, but the pump would not come on. He replaced the pump and so far that has taken care of the the problem.
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Tuesday, November 24th, 2020 AT 7:41 AM (Merged)
Tiny
A.MERIDETH
  • MEMBER
  • 2 POSTS
  • 2001 FORD RANGER
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 110,000 MILES
Fuel pump will not "whine" occasionally. Becoming more frequent. Engine will turn over, just no whine. Will start after several attempts. Occurs with full tank or at one-fourth. (Or anywhere inbetween) Checked relay, good. Is my pump going bad?
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Tuesday, November 24th, 2020 AT 7:42 AM (Merged)
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,053 POSTS
It could be that the pump is going bad, it could have a weak ground, or the relay is only working on and off. Has the truck ever died on you while driving? Also, have you ever checked fuel pump pressure and pressure drop off?

Let me know. If you need directions, let me know.

Joe
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Tuesday, November 24th, 2020 AT 7:42 AM (Merged)
Tiny
A.MERIDETH
  • MEMBER
  • 2 POSTS
No problems when running at all. Have not started checking anything other than the relay fuse (20a) I left the fuse in, it was not blown. I did not know it could still possibly be an issue (working intermittenly).
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Tuesday, November 24th, 2020 AT 7:42 AM (Merged)
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,053 POSTS
Actually, I was refering to the relay itself and not the fuse. You are correct. The fuse is either good or bad. There is a relay that is under the hood in the power distribution center. It may be going bad. What to do is in that relay box, find the fuel pump relay and switch it with another relay that has the same part number to see if you have the same problem. If you do, then the relay isn't the problem. NOTE: When you open the relay block, there is a printed list on the lid that indicates what each relay is for. Make sure if you try this to make sure to pick a relay with the same part number to switch.

Let me know what you find.

Joe
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Tuesday, November 24th, 2020 AT 7:42 AM (Merged)
Tiny
JOE1953
  • MEMBER
  • 677 POSTS
  • 1999 FORD RANGER
  • 2.4L
  • 4 CYL
  • RWD
  • MANUAL
  • 186,000 MILES
Fuel pump is not working the fuses, relay, and the reset switch been check. How do I replace the fuel pump or fuel pump assembly? What I have to do?
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Tuesday, November 24th, 2020 AT 7:43 AM (Merged)
Tiny
WRENCHTECH
  • MECHANIC
  • 20,761 POSTS
You have to do one of two things. You either have to remove the fuel tank or lift the bed off the frame and access it from there.
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Tuesday, November 24th, 2020 AT 7:43 AM (Merged)
Tiny
JOE1953
  • MEMBER
  • 677 POSTS
Which is the easy way remove the tank or lift the bed?
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Tuesday, November 24th, 2020 AT 7:43 AM (Merged)
Tiny
WRENCHTECH
  • MECHANIC
  • 20,761 POSTS
It is personal preference of whatever you find easier. The bed has three or four bolts on each side. Remove them all from the left side and back them way off on the other side. Disconnect the wiring and filler pipe and lift one side of the bed. Just be very careful to be sure to insert some kind of safety blocks to insure that bed can't fall on you.
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Tuesday, November 24th, 2020 AT 7:43 AM (Merged)
Tiny
JOE1953
  • MEMBER
  • 677 POSTS
What do I use to lift the bed of the frame?
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Tuesday, November 24th, 2020 AT 7:43 AM (Merged)
Tiny
WRENCHTECH
  • MECHANIC
  • 20,761 POSTS
I use a pole jack at the wheel opening.
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Tuesday, November 24th, 2020 AT 7:43 AM (Merged)
Tiny
JOE1953
  • MEMBER
  • 677 POSTS
How do I test the new fuel pump before I bolt the fuel tank on? I am replacing the fuel pump assembly.
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Tuesday, November 24th, 2020 AT 7:43 AM (Merged)
Tiny
WRENCHTECH
  • MECHANIC
  • 20,761 POSTS
You can apply power and ground to the pump to test the pump itself but you can't test the rest of the circuit until you have all the wiring and hoses connected. These are tests that should have been run BEFORE changing the pump.
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Tuesday, November 24th, 2020 AT 7:43 AM (Merged)
Tiny
ALLEN09
  • MEMBER
  • 1 POST
  • 1999 FORD RANGER
  • 6 CYL
  • 4WD
  • AUTOMATIC
  • 128,000 MILES
Why would my fuel pump not be getting power. It just died on me and acted like it wouldnt get fuel. My battery light came on, my check engine light has been coming on and off. I have changed my fuel pump and fuel relays Please help
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Tuesday, November 24th, 2020 AT 7:43 AM (Merged)
Tiny
PROTECH1980
  • MEMBER
  • 901 POSTS
Have you checked the interia fuel cutoff switch? Your Ford truck should have one located passenger kick panel area, as for the CEL, you will have to get the truck scanned for codes for diagnoses, as for the batt. Light, check and test charging system.
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Tuesday, November 24th, 2020 AT 7:43 AM (Merged)
Tiny
WRENCHTECH
  • MECHANIC
  • 20,761 POSTS
To add to this, make sure you are testing it properly. It only powers for 2 seconds when the key is first turned on. It then restarts when the PCM sees a tach signal from cranking.
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Tuesday, November 24th, 2020 AT 7:43 AM (Merged)

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