Fuel Pump 2008 Adventure

[Bendy toy]

Can anyone tell me the symptoms of a weak fuel pump?

The bike has recently been running out of fuel with about 8 litres (ish) remaining in the tank. The jet pump pipes are sitting correctly (checked yesterday) so maybe low fuel pressure is causing a weak return flow. Fuel pump intake filter is clean.

It starts fine and runs at OMG speeds with no issues but it can stutter in traffic.

I don't have a GS-911 so is there a test for fuel pump performance?

 

[Kenny Rodkiss]

I think what you have is 'the test' for a tired fuel pump.
Sucking jet pump relies totally on a sufficient fuel return flow to operate. Inadequate return flow=no fuel transfer, means the left side runs dry with a good few litres still in the right side.

 

[Bendy toy]

That was my thinking but I like to confirm by other means if poss.

I saw somewhere (but now can't find it so could be complete tripe) that the return fuel flow should be 2 litres per minute at tickover. Can anyone confirm that? It's easy enough to fill a spare fuel can and do the sums.

At least replacement pumps are not too costly on Fleabay. Has anyone tried them?
http://www.ebay.co.uk/itm/BMW-R1200...022579?hash=item2363ab3f33:g:1zMAAOSwKtVW0FiX

 

[Pukmeister]

Do a search, theres an old thread somewhere about a replacement Bosch fuel pump rotating element in a GSA.

 

[Kenny Rodkiss]

Adv rider reading points to the pump with some flow rates,http://advrider.com/index.php?threads/r1200gs-fuel-pump-return-flow-rate.688611/

 

[Bendy toy]

Ive read through the advrider thread. It looks like either my fuel filter is clogged or fuel pump is weak. The filter would be annoying but easily resolved with an external inline filter and bodge holes through the dirty filter element- probably.

Replacement pumps are low cost on eBay so worth the try.

 

[Kenny Rodkiss]

Was interesting that when by passing the the pump controller and running the pump straight from 12v that they get a better output, as if the controller was overly reducing the pump action?

 

[Bendy toy]

The bike has performed fine until I opened the tank to fit a float level gauge. I fully drained the tank but the pump wasn't touched (apart from remove & refit). Everything looked really clean inside so I doubt the filter is blocked.

However one person commented (on advrider) that the pump controller runs the pump at a higher duty cycle when the tank is low. My fuel strip has been reading zero level for months, but I have now chucked it and at the very next tankful I ran out with 2 gallons remaining.

Maybe that low fuel signal has been continually running the pump harder and hiding it's getting weak. Next step is to see if a controller bypass wire solves the tank emptying issue

I wonder if people using the fuel gauge resistors mod to spoof a full tank reading are more likely to suffer tank emptying issues.