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Discussion Starter · #1 ·
I'm trying to help a friend with a 2007 K1200S with fuel supply issues. He changed the pump (the one fitted was all rusty and horrible inside) and also has a replacement secondhand fuel pump controller but it won't work correctly. When supplying the pump directly with power it works and the bike runs, but nothing with the FPC connected. There seems to be no +12v at the 3 pin connector for the FPC, is there a relay that could be the issue or is it likely that both the original and replacement FPC's are faulty? I would expect to see +12v at the connector at switch on?
 

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If I remember correctly, the fuel pump only runs when the bike is running. There is only 12v at the connector when the starter motor is pressed, and/or the bike is running. With only ignition on, there is no power to the pump.

I'd check the connector again for power when pressing the starter motor.

I was testing a quick connector, and to get fuel to run I had to press the starter motor.

On saying that, it is possible that the two FPCs are faulty. They have been known to corrode and fail, but more on the GS's as they are more exposed. When you say it ran when you supplied power to the the pump, was it from another source, or through the FPC?
 

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I think your second FPC is dead also. Buy a new one. Picture of one that is NFG. Use dielectric grease on the connectors for the new one. and the controller gasket also.
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Discussion Starter · #4 ·
Many thanks for the replies, it's all helpful. One other thing I'm curious about is does it make any difference to the FPC whether the fuel sender is connected and/or if so, if it's reading correctly?

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Many thanks for the replies, it's all helpful. One other thing I'm curious about is does it make any difference to the FPC whether the fuel sender is connected and/or if so, if it's reading correctly?

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No there is no connection between them.
 

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And when you're swapping it out, replace the quick-connects with metal ones.
I don't have a link to the European supplier. but what you want is 6mm fuel quick connects. female and 90degree male.
 

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The female is a problem in the making. It is possible to install it too deep and split the fuel pump bulkhead flange. It needs fuel proof thread dope. So only tighten it up to snug, like 6Nm. Because of this difficulty I would only suggest changing the male fitting unless you are familiar with pipe fitting and its problems with threaded fittings.
 

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What beech said... it's a tapered fitting, so you're screwing a wedge into a plastic housing. Recipe for disaster (don't know why BMW thought it was a good idea, it led to a massive recall, and is fitted across a large range of bikes).. i did change the one on my friends K1200, because it was leaking. I put a screw clamp around the outside boss of the fuel pump housing, then replaced the fitting, using the supplied thread dope. I tightened it snug. I didn't bother replacing the fitting on my bike as it wasn't leaking, so left well enough alone.
 

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You need one of these to test with to see if it really is the controller.


Here is a good source for the FPC. Less than half what bmw wants, made by the company that makes them for bmw.

 

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Discussion Starter · #11 ·
If I remember correctly, the fuel pump only runs when the bike is running. There is only 12v at the connector when the starter motor is pressed, and/or the bike is running. With only ignition on, there is no power to the pump.

I'd check the connector again for power when pressing the starter motor.

I was testing a quick connector, and to get fuel to run I had to press the starter motor.

On saying that, it is possible that the two FPCs are faulty. They have been known to corrode and fail, but more on the GS's as they are more exposed. When you say it ran when you supplied power to the the pump, was it from another source, or through the FPC?
Not had chance to get back on this until today so will check for 12v at the connector on cranking this morning.
Regarding the pump, it runs fine when supplied directly from the battery.
 

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Discussion Starter · #12 ·
Update - Well, the bike runs! I have a couple of extra questions you guys might be able to help with:

If a FPC goes bad, is it permanently bad or can it work intermittently, say for example can an internal component break down and cause it to fail when warm but operate when cold?

On the signal wire from the 3 pin connecter to the FPC, I'm seeing only between about 2v and 2.27v, is this normal?
 

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From my aging memory.... the FPC is a printed circult board, so they are prone to corrosion, but as I said, normally not on the Ks due to the position. A bad/intermittant connection can't be ruled out.

Also, the three wires, one is earth, one is 12v power and the other is dictated by the engine revs, so the pump only pumps as needed rather than full bore all the time. That is the 2v you are getting. It should change if you rev the bike.

So as you can see from the link above, it is possible to bypass the FPC in an emergency, but it will mean the pump is running full pressure all the time, hence only a "get you home" solution.
 
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