GSX1250FA - FI Fuel Starvation

[Mercaholic]

Starts when cold and runs good for about 10 min then bogs at any attempt to get over 4000 rpm, in any gear.

If fuel is low, it is worse and stuggles to get up to any speed.

I cleaned fuel filter atho it was quite clean, with no change

Does this sound like a weak fuel pump matter?

[chuck hahn]

Fuel pump would be my go. Once its running dump a 1/2 a can of Berrymans fuel injector cleaner in and take a good 50 mile trip. Then add the wsecond half into the n3xt tank of gaS.

[chuck hahn]

If you dont have a fuel pressure gauge undo the line going to the fuel rail and put your finger over the line and turn on the key. If you dont feel a good amount of pressure trying to get gas past your finger...much like when you put youur finger over a garden hose...the pump is most likely weak.

[KEITH KRAUSE]

Are you positive the air cleaner is OK/drawing enough air?

[GregT]

On carbs it's a classic blocked tank vent. Can still happen with FI.

[chuck hahn]

Both good points

[steve murdoch]

Does your bike have an O2 sensor?

I just read a post about a second, small fuel filter inside the pump? Might be something else to check.

[bwringer]

No idea about El Bandito Grande, but on the V-Strom DL1000 there's a tiny filter deep inside the fuel pump about the size of a 25 cent pack of gum. This badly undersized filter inevitably clogs at some point, usually around 30-50,000 miles. The fix is to drill a hole in the fuel pump body to bypass the filter and then install an external filter.

Suzuki has a well-known penchant for parts bin engineering, so that's the sort of thing I'd investigate. There's a fuel volume test that's easy to do -- basically take the output hose off, direct the fuel into a container, then cycle the key three times and see what sort of fuel volume you get. If it's below a certain point, then the pump is clogged, weak, or otherwise damaged.

It's also not unknown for the pump motor to come unseated from the plastic pump "frame" slightly -- it snaps into place with an o-ring seal, and if it's not seated completely and firmly, it won't build pressure.

No idea about Canada, but in the US you can borrow specialized tools like fuel pressure testers from most chain auto parts stores.

Blocked vent is also worth investigation.

[Mercaholic]

Thanks guys.

I did pull the pump out and clean the two filters. There wasn't any debris to be found.

I've checked the vent hoses with the tank was off.'

This bike is a '12 model with only 7500 miles on it so now wondering if the pump gets weaker as it runs. It operates fine at start but gradually seems to degrade.

I've ordered a replacement pump this morning so will send an update when installed.

[Mercaholic]

Bought a rplacement fuel pump off Amazon.

Came from China but was less than half the price from dealer.

Now installed and back to normal.

Thanks for the help guys...!

[KEITH KRAUSE]

Glad you're back on the road!

[Mercaholic]

An update.

Well my cheap Chinese fuel pump from Amazon lasted about 2K miles and wore out. No sign of a dirty fuel filter. When I shake it, I can hear a internal rattling sound

It went from an output of 40psi when new to 12psi today.

Ordering a new one and will gladly pay for a good one.

Lesson learned....

[bwringer]

Thanks for the follow-up!

There are only a few manufacturers of the actual fuel pump/motor units, and only so many sizes. I know over in the V-Strom world, some folks have figured out which car models use a compatible pump, and how to transplant it into the bike's fuel pump housing, so you can order a better quality unit from RockAuto.

Has anyone figured this out for Bandits yet?

[Rijko]

Might be worth checking the OEM fuel pump again.

Several Bandit forums report the same thing, hard to see/find fuel pump contamination.

Here's a sticky from the Aussie forum, with some good pictures : https://nswbandits.forumotion.net/t1379-fuel-pump-fix