Fuel pump problem

Tiny
JESSEJAMES921
  • MEMBER
  • 1993 FORD RANGER
  • 180,000 MILES
I was driving then all of a sudden truck quit running and fuel pump will not turn on with switch, all fuses and relays are working, I have 12v power at fuse box under hood at fuel pump relay but its not making it to the fuel pump, im at a loss on what to do can anyone help
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Monday, April 29th, 2013 AT 8:40 AM

14 Replies

Tiny
HMAC300
  • MECHANIC
  • 48,606 POSTS
Look for a shorted wire or make sure your inertia switch isn't engaged. I think it is on right kick panel just forward of door
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Monday, April 29th, 2013 AT 9:56 AM
Tiny
JESSEJAMES921
  • MEMBER
  • 3 POSTS
The switch is not engadged. And I cant seem to find any shorted wires. The main power to pump will have power to it only when harness is undone from fuel pump. When I connect the harness to pump and check the wires for power it turns to a full ground with switch on or off
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Monday, April 29th, 2013 AT 1:20 PM
Tiny
HMAC300
  • MECHANIC
  • 48,606 POSTS
Sounds like a bad pump then
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Monday, April 29th, 2013 AT 1:27 PM
Tiny
JESSEJAMES921
  • MEMBER
  • 3 POSTS
Im thinkin I shorted the pump out somehow. I have a power probe that if I put power to pump through the main wire it will kick on so thats what got me confused
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Monday, April 29th, 2013 AT 1:37 PM
Tiny
STEPHENMOORE
  • MEMBER
  • 4 POSTS
  • 1989 FORD RANGER
  • 130 MILES
After running without incident 2 days earlier I accidentally left the ignition on.
After charging the battery, the engine would crank but showed no signs of starting.

I noticed there wasn't an audible fuel pump noise when ignition was switched on. (Pump/sending unit are approx 1.5 years old.)
After determining the pump would operate with direct voltage I checked fuel pump relay, inertia switch and (because of a forum post) the EEC relay.
When truck would not start after making fuel pump run continuously I checked for spark. None exists.

I checked coil, coil wire and distributor mechanism. The TFI could be at fault for a lack of spark but I don't think it has anything to do with the fuel pump.

Whatever is at issue controls both fuel and spark.

Unfortunately the only item I am aware of that controls both tasks is the ECM.

My next task is to see if I can detect any error codes.
Being an '89 these are very simplistic.
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Tuesday, November 24th, 2020 AT 8:54 AM (Merged)
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,797 POSTS
You are on the right track. The ecm grounds the eec relay for the spark and fuel to operate. A scan tool would help to see if any info is coming from the ecm check all powers and grounds for the ecm.

Roy
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Tuesday, November 24th, 2020 AT 8:54 AM (Merged)
Tiny
STEPHENMOORE
  • MEMBER
  • 4 POSTS
Thanks, will do.
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Tuesday, November 24th, 2020 AT 8:54 AM (Merged)
Tiny
STEPHENMOORE
  • MEMBER
  • 4 POSTS
Couldn't find anything on youtube but did find my code reader.
Unfortunately it's been separated from it's manual. (I have 2 for the GM reader.)
This may be a moot point because when I plug the reader in the light stays on continously.
Turning the ignition on makes no difference.
Jumping the single test wire to ground makes no difference.
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Tuesday, November 24th, 2020 AT 8:54 AM (Merged)
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,797 POSTS
Code reader will give you no info, just codes. You need a full blown scan tool.

Roy
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Tuesday, November 24th, 2020 AT 8:54 AM (Merged)
Tiny
JWALLACE08
  • MEMBER
  • 3 POSTS
  • 1988 FORD RANGER
I have a 1988 Ford Ranger with a 2.9L V6. This model has (2) fuel pumps. I have recently replaced both myself. It has been roughly 2 months since I replaced them. My truck runs great, when it starts. This past weekend when I tried starting the truck the fuel pumps would not run. 24 hours later I tried to start again and it started, both fuel pumps were operating. I know that the problem is electrical but I am stumped for ideas.
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Tuesday, November 24th, 2020 AT 8:54 AM (Merged)
Tiny
TAURUSWHEEL
  • MECHANIC
  • 718 POSTS
Any chance that truck has an integrated controller module or some thing similar? Usually, on the car models, was mounted on the radiator upper support, under the sight shield. Small black box with a big connector bolted to it, lots of wires. In that box were fuel pump relay, ac relay, and others. I don't know if they're serviceable, on the cars the box was riveted.
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Tuesday, November 24th, 2020 AT 8:54 AM (Merged)
Tiny
JWALLACE08
  • MEMBER
  • 3 POSTS
I did some work on the pickup this weekend. I discovered that somewhere in the EFI electronics there is a switch sticking or broken. I re-routed my fuel pump wiring to my acc. In my fuse box put a toggle switch on the dash. Fuel pumps work great now. Thanks for your help.
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Tuesday, November 24th, 2020 AT 8:54 AM (Merged)
Tiny
BHUGG
  • MECHANIC
  • 157 POSTS
I don't know if this will help.
On my 93 explorer, there are 2 possibilities. There is a fuel pump relay that is in the power distribution box. This is under the hood. Look for a box with a bunch of relays and fuses in it. I personally have had 2 relays go out in this box. There is also a 20a fuse to this circuit in the box.
My Explorer also has an "inertia fuel shutoff" sensor that will open the circuit to the fuel pump on impact.
On mine, it is behind the instrument panel on the passenger side. From the diagram I have, it appears to be mounted to the fire wall.
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Tuesday, November 24th, 2020 AT 8:54 AM (Merged)

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