Fuel Pump filters | GTAMotorcycle.com

Fuel Pump filters

Merkid

Well-known member
I just finished working on a Bud's DL1000 Vstrom.

He stored it with a full fuel tank for a year and went to start it recently. He said it fired right up, ran for a km but sputtered and lost power. He said he barely got it home as it would only rev up to 2K rpm.

We suspected bad fuel so drained the tank and added new stuff and it didn't help. We pulled the tank for cleaning and noticed the fuel filter looked like a broken tea bag . The tank contained small bits of the fuel filter thru out.

We think the fuel pump sucked all the bits up and clogged things. A new fuel pump and regulator is on order.

Could this be resulting from the Ethanol in the fuel ?
 

GreyGhost

Well-known member
Site Supporter
Maybe? With storage for a year, there is also a chance that the Ethanol picked up water and the filter was sitting in that crap. If that was the case, I would have expected more issues getting it going though. I only store vehicles with Shell 91 to avoid having to think about fuel schmoo as my issue.

How far do you think that crap travelled? Is there another filter at the regulator? Do you think it made it to the injectors? I might use some compressed air and fuel to do a ghetto flow test on them (obviously in a well ventilated area as this is dangerous).

Apparently an external fuel filter is a common mod for that bike.
 

J_F

gringo diablo
Site Supporter
+1 on the no-ethanol for last tank of the year
even if you don't need the octane rating

stored in non climate controlled conditions?
 

Merkid

Well-known member
There could be more filter particles stuck within the pump housing but we hope nothing made there way to the injectors. We did apply compressed air to the whole assembly and could see some minute things fly out....(n)
 

TK4

Well-known member
Immerse the pump in a pail of Varsol and hook up a 9 volt dry cell battery. See what comes out ?
 

Trials

Well-known member
I just finished working on a Bud's DL1000 Vstrom.

He stored it with a full fuel tank for a year and went to start it recently. He said it fired right up, ran for a km but sputtered and lost power. He said he barely got it home as it would only rev up to 2K rpm.

We suspected bad fuel so drained the tank and added new stuff and it didn't help. We pulled the tank for cleaning and noticed the fuel filter looked like a broken tea bag . The tank contained small bits of the fuel filter thru out.

We think the fuel pump sucked all the bits up and clogged things. A new fuel pump and regulator is on order.

Could this be resulting from the Ethanol in the fuel ?
You sure that is the only filter? there should be something better then that on a fuel injected bike.
 

Trials

Well-known member
I think that might be just a strainer, the fuel filter is usually on the high pressure side of the fuel pump, that's why they are usually in a metal canister.
 

Trials

Well-known member
Now find the paper fuel filter and you will find all the little pieces of your plastic strainer. Anything that was not completely dissolved went through your fuel pump and hopefully got stopped by the fuel filter, because nothing solid is going to pass through your injector nozzles.

"He said it fired right up, ran for a km but sputtered and lost power. He said he barely got it home as it would only rev up to 2K rpm."
Symptom of low fuel pressure, your filter is pugged, or the canister is split open, or you have a leaking fuel line somewhere, might even be inside the tank.
Look for bubbles and fluid currents inside the fuel tank where they should not be.

... I bet your pump and fuel pressure regulator are just fine and your fuel filter or plumbing is the problem.
Sometimes the manufacturer does not offer the filter individually and only sells it as an assembly in combination with the fuel pump. ymmv
Sometimes you can rebuild service the entire fuel pump and filter assembly yourself.
 
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oomis

Well-known member
Site Supporter
"He said it fired right up, ran for a km but sputtered and lost power. He said he barely got it home as it would only rev up to 2K rpm."
Symptom of low fuel pressure, your filter is pugged, or the canister is split open, or you have a leaking fuel line somewhere, might even be inside the tank.
From my former vstrom days, the fuel filters are a 2 stage unit, one for low throttle opening and one for higher throttle openings. I had this issue in Wyoming. There's a hack you can find on the Stromtrooper website that involves drilling a hole to bypass and installing an external fuel filter in the middle of the line. Means the high opening filter is done and this is a way to fix it without spending $$ on a new part.
 

Trials

Well-known member
Would be super easy to put an additional filter on the return line of my BMW, but there would be less percentage to filtering the fuel after the part I don't want to plug with dirt. Still might work to keep the fuel cleaner and water free because a lot of fuel continuously cycles past the injectors, through the fuel rail and returns to the tank on K bikes. Would be even better if I could Cool the return fuel on that bike. She heats the fuel up pretty good, as I think they all might do on occasion.
 

Brian P

Well-known member
Moderator
Site Supporter
All later model motorcycle fuel injection systems that I have worked on or seen, are returnless designs. The bike referred to in the original post, will be a returnless design.

There may or may not be a non-replaceable secondary filter inside the sending unit (the plastic assembly that houses the pump itself). Or the pump may have been trashed. The secondary filter will be on the pressure side of the pump. If the inlet strainer fails, it won't stop trash from getting into the pump.

I've back-flushed a secondary filter in the course of replacing the pump. A lot of black crap came out ...

If there's no secondary filter, trash may have gotten into the injectors. That's a nuisance.
 

Trials

Well-known member
Ew, I just looked at the DL1000 parts diagram :/ two stage throttle body controlled by what? vacuum or electric. Either way it adds a layer of complexity to your trouble-shooting.

... nothing that brand new injectors won't fix once you fix all the filter and throttle control issues.
 

Brian P

Well-known member
Moderator
Site Supporter
The dual-throttle setup is common in that generation of EFI systems. My 2004 ZX10R is the same way. The throttle closest to the intake valves is operated manually by cables from the rider's control, the upstream one is drive by wire operated by an ECU controlled stepper motor. It lets the system emulate the traditional CV carb vacuum slide for better driveability at low revs. This was an era before full drive by wire was accepted. It's not an issue insofar as the original poster's problem is concerned.
 

Trials

Well-known member
Modern fuel injection (without the extra butterflies) is such a bonus to performance and reliability it's shocking.
You have to drop the bike into the lake to make it miss a beat. Even then it will fire 3 times under water :LOL: I know this from experience.
 

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