Author Topic: Fuel pump keeps running.....is this normal?....SOLVED  (Read 9476 times)

Offline surreybeemer

  • Motobrick Curious
  • Posts: 12
Fuel pump keeps running.....is this normal?....SOLVED
« on: December 24, 2015, 11:29:14 PM »
Hi fellow K riders...
I noticed that the fuel pump on my 1987 k75s keeps running as long as the ignitions key is in the on position even if the engine is not running.  I thought it is suppose to stop after a few seconds if the engine is not turning like in most cars.  I am not sure if this is normal or I have some problem that needs attention. 
Thanks!!
  • Surrey BC Canada
  • BMW r50/2, r50/5 r65ls and K75s

Offline Inge K.

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  • Posts: 1451
Re: Fuel pump keeps running.....is this normal?
« Reply #1 on: December 25, 2015, 07:28:26 AM »
The fuel pump should only run when the engine running, or the start button is pressed.
The negative side of the FI relay coil is controlled by the ignition ECU.

It sounds to me that the problem is the ignition ECU (behind the headstock), or the wire
between the relay and ECU is shorted to ground (colour code, brown/yellow).
  • Norway

Offline Scott_

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Re: Fuel pump keeps running.....is this normal?
« Reply #2 on: December 25, 2015, 09:30:25 AM »
More unlikely, but it could also be a stuck relay.
  • My Garage
1995 K1100LT 0302044
2017 FLHTK Ultra Limited
1997 K1100LT 0302488 (R.I.P.)
1997 R1100RT ZC62149(sold)
"One who does not ask questions is ashamed to learn" Danish proverb

Offline Inge K.

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Re: Fuel pump keeps running.....is this normal?
« Reply #3 on: December 25, 2015, 10:00:07 AM »
More unlikely, but it could also be a stuck relay.

Then the fuel pump also would run with the ignition switch in the off position.
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Offline Gio

  • ^ Proficient Motobricker
  • Posts: 217
Re: Fuel pump keeps running.....is this normal?
« Reply #4 on: December 25, 2015, 12:31:35 PM »
Drain entire fuel system and then flush with a 50/50 mixture of egg-nog / brandy. If no joy - re-drain and drink proceeds ... this won't fix the problem but will give you an entirely different perspective ...

Wishing you all the seasonal best fellow 'brickers!

Gio
  • NS, Canada
  • K75s ("Buttercup")
Halifax, NS
1994 K75s (UK spec)
1984 Honda 200ES (Big Red)

Offline Scott_

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Re: Fuel pump keeps running.....is this normal?
« Reply #5 on: December 25, 2015, 01:32:02 PM »
More unlikely, but it could also be a stuck relay.

Then the fuel pump also would run with the ignition switch in the off position.

Makes sense.
  • My Garage
1995 K1100LT 0302044
2017 FLHTK Ultra Limited
1997 K1100LT 0302488 (R.I.P.)
1997 R1100RT ZC62149(sold)
"One who does not ask questions is ashamed to learn" Danish proverb

Offline KRider

  • Motobrick Curious
  • Posts: 25
Re: Fuel pump keeps running.....is this normal?
« Reply #6 on: December 26, 2015, 04:54:20 AM »
I have have almost the same but i can controle it with the deadmans button.

Offline Inge K.

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Re: Fuel pump keeps running.....is this normal?
« Reply #7 on: December 26, 2015, 05:06:21 AM »
I have have almost the same but i can controle it with the deadmans button.

It's just the same, if the ignition switch or kill switch is used.
It's just cuts the power to the FI relay coil on different places along the line.
.
.
.
But if you have a 4V model the fuel pump runs for a couple of seconds and then stops,
when you turn on the ignition switch (or kill switch)...this builds up the fuel pressure.
  • Norway

Offline KRider

  • Motobrick Curious
  • Posts: 25
Re: Fuel pump keeps running.....is this normal?
« Reply #8 on: December 26, 2015, 12:18:16 PM »
Thanks Inge K so surreybeemer and me have same problem. Will look at it soon.

Offline surreybeemer

  • Motobrick Curious
  • Posts: 12
Re: Fuel pump keeps running.....is this normal?....SOLVED
« Reply #9 on: January 17, 2016, 08:49:11 PM »
Finally it is all good.  I took the fuel pump out, cleaned all the connections going to the fuel pump.  Also cleaned the low fuel light mechanism attached to the float, it was rusty and gummed up.  Cleaned the connections under the tank and to the ECU.  Put it back together and it works normally.  I can hardly hear the pump running and no more whizzing noise.  The bike starts with one light push on the button...it is all good.
Big Thanks to you guys!!
Here is a pic of the final product.
  • Surrey BC Canada
  • BMW r50/2, r50/5 r65ls and K75s

Offline WayneDW

  • ^ SuperNatural Motobricker
  • Posts: 638
Re: Fuel pump keeps running.....is this normal?....SOLVED
« Reply #10 on: January 17, 2016, 10:32:22 PM »
Beautiful bike!
  • Minneapolis, MN, USA
  • 1992 K75RT

Offline The Mighty Gryphon

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Re: Fuel pump keeps running.....is this normal?....SOLVED
« Reply #11 on: January 18, 2016, 10:23:38 AM »
The K75S, porn star of the K bike line...
  • In my garage in Marilla, NY
  • '91K100RS White/Blue
Current:
'91 K100RS16V "Moby Brick Too"

Past:
'94 K75RT "Ilsa, She Wolf of the SS"
'92 K100RS16V "Moby Brick" (RIP, deceased in a vehicular assault)
'94 K75S Special Edition Dakar Yellow "Cheetos"
'89 K100RS Special Edition "Special Ed"

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