Fuel pump controller......again!

[Senslesssquid]

Hello everyone.
2009 GSA with the dreaded, no fuel pump issue. I was left stranded on exmoor for 6 hrs before being recovered at midnight.
Since getting it home, and researching the issue I made the bypass lead and the bike runs fine now.
But what I find strange is the relay/controller give voltage when unattached to the pump of 11v. Dropping to 8 when running. But as soon as I reattach it to the pump I can't find any voltage coming from it?
Any ideas, before I just go ahead and order a new one??

 

[botus]

so the idiots have variable fuel pressure - what utter insanity, so the spray pattern at low revs is the cause of hopelessness my GS struggles to run under - and at high speed they rev it up and overfuel by 20% as the Lambda sensors aren't involved on full throttle - MORONS

]https://www.k-bikes.com/attachments/daspump-pdf.37790/

 

[Mistacat]

If you watch the fuel pressure it does not vary under any conditions, 3.5 bar pre twin cam 4 bar twin cam.
At full voltage the pressure is governed by the pressure relief valve in the fuel pump which can be around 8 bar.
The fuel pressure regulator in the injector circuit keeps the pressure constant at 3.5 bar and 4 bar.

 

[botus]

I guess that's where your gauge helps you know that - the document suggests otherwise.... why bother to play if the end result is consistent ?

oh yeah, an extra point of failure, so they can try and screw you on diagnostics and fitting something it doesn't need

 

[Senslesssquid]

So what's your advice guys, should I just buy another fuel pump regulator or run it without one?

 

[Mistacat]

As stated in the previously inserted link ]https://www.k-bikes.com/attachments/daspump-pdf.37790/
The controller reduces the load on the pump, this stops the pump running flat out when say idling or cruising at 30mph as it is linked to fuel consumption.
The life of these pumps is not very long, I change mine every 40k miles as a service part so they need all the help that they can get.
The bypass cable is handy to get you home ( I have one in my bike tool kit just in case).
If I ever had a fuel pump controller fail I would replace it at the earliest opportunity.

 

[Senslesssquid]

As stated in the previously inserted link ]https://www.k-bikes.com/attachments/daspump-pdf.37790/
The controller reduces the load on the pump, this stops the pump running flat out when say idling or cruising at 30mph as it is linked to fuel consumption.
The life of these pumps is not very long, I change mine every 40k miles as a service part so they need all the help that they can get.
The bypass cable is handy to get you home ( I have one in my bike tool kit just in case).
If I ever had a fuel pump controller fail

OK, so you replace the whole fuel pump with a cheap ebay one. But does that come with a fuel pump controller?

 

[theoneandonly]

The life of these pumps is not very long, I change mine every 40k miles as a service part so they need all the help that they can get.

you change the pump @40k , that's ridiculous , that you should have to do that . are they failing ? or are you being really cautious ? or are they really cheap and nasty ones ?

 

[Mistacat]

The first one failed at 43K , I machined the crimped end off the pump and the brushes were toast.
Fitted cheap ebay pumps £25, the orifice in these pumps pressure relief valve is too small and they were swamping the main fuel pressure regulator so was running 1.5 bar over pressure, this took a lot of finding. Now run a pump from motorworks ( manufactured from OEM supplier )
This seems really good. I have a 40mm pressure gauge on the dash so when the pump starts to fail I can change it.
The bike will run on a fuel pressure below 2bar but I have recorded a Air fuel ratio as lean as 18 to 1 easier to change a pump than a burnt or dropped exhaust valve.

 

[Senslesssquid]

The first one failed at 43K , I machined the crimped end off the pump and the brushes were toast.
Fitted cheap ebay pumps £25, the orifice in these pumps pressure relief valve is too small and they were swamping the main fuel pressure regulator so was running 1.5 bar over pressure, this took a lot of finding. Now run a pump from motorworks ( manufactured from OEM supplier )
This seems really good. I have a 40mm pressure gauge on the dash so when the pump starts to fail I can change it.
The bike will run on a fuel pressure below 2bar but I have recorded a Air fuel ratio as lean as 18 to 1 easier to change a pump than a burnt or dropped exhaust valve.

Have you any experience with Quantum HFP-382-B fuel pump? I've read about an external fuel filter?

 

[Mistacat]

I have not tested the Quantum pump after the problems I had with Ebay pumps I went with the VDO pump sold by motorworks at the time for around £50.
VDO are owned by Continental who make the OEM housing etc.
I reverse flushed my filter ( the fitted for life unit in the pump housing) which ruined it ,So I drilled it through ( there is a post on here regarding this) and now use a R1150GS inline filter.
I think Autodoc supply VDO pumps but that will require further research for my next pump.

 

[Pukmeister]

Have you any experience with Quantum HFP-382-B fuel pump? I've read about an external fuel filter?

I fitted one when I had my Hexhead, along with modifying the plastic pump casing to drill out the internal moulded filter and fit a Mahle high pressure external fuel filter.

As Mistacat has diagnosed with his mechanical fuel pressure gauge, the pump performance falls off around 45k and is worth replacing if you experience slow acceleration from moderate speeds when giving it hard throttle.

 

[Senslesssquid]

I have not tested the Quantum pump after the problems I had with Ebay pumps I went with the VDO pump sold by motorworks at the time for around £50.
VDO are owned by Continental who make the OEM housing etc.
I reverse flushed my filter ( the fitted for life unit in the pump housing) which ruined it ,So I drilled it through ( there is a post on here regarding this) and now use a R1150GS inline filter.
I think Autodoc supply VDO pumps but that will require further research for my next pump.

Reversed flushed? Accidentally got the polarity wrong when bypassing the control unit?

 

[Mistacat]

No.. Reverse filled it with fuel and put the airline on it at 150 psi ( reverse flushed) The internal filter is not capable of standing this kind of abuse

 

[DrFarkoff]

No.. Reverse filled it with fuel and put the airline on it at 150 psi ( reverse flushed) The internal filter is not capable of standing this kind of abuse

A "Tad" on the high side, pressure wise, there old bean!!!

 

[Mistacat]

Yep, not thinking picked up the wrong airline ( the one without the pressure regular on it) and gave it a quick squirt

 

[Senslesssquid]

I've made a direct feed to the pump. What is the best size fuse to use? 5amp?

 

[Mistacat]

Look at the Quantum Specs , You will need at least a 10 Amp fuse if you are running it flat out without a controller.

 

[Senslesssquid]

Look at the Quantum Specs , You will need at least a 10 Amp fuse if you are running it flat out without a controller.

Thank you, I put a 5amp in and it was blowing, so went up to 7.5 that it runs fine on. But you think 10 is the way to go?

 

[Mistacat]

The Quantum pump draws 8 amps at 13.5 volts hence I suggested 10 Amp minimum fuse.
The only reason I did not use the Quantum pump is that I once had a fuel pressure regulator from them which was slightly oversize to the point that I thought it was going to crack the plastic housing when fitting. I did not get any help from them.
The pump from motorworks that I now use came in a Continental box as OEM and the Motorworks part number is FUA84025 .
The price is higher than I remembered at £84.50.