Gen 1 fuel pump

[woodlandtechie]

I've just stipped my fuel pump for cleaning, had no real issues until I removed the pump itself from the housing....the plastic cage which has the screen on the inlet is stuck in the pump body.

Now the plastic cage looks a little brittle, I've tried to gently prise it out but it feels quite tight in there....does anyone have any idea how I can remove this without damage?

 

[pashnit]

Just rebuilt/cleaned/new filter for my '00 fuel pump (what a huge pain), but I can't picture what you're describing here.

Possible to post pics?

 

[Vigosama]

I read somewhere on here about using compressed air to shoot it out.

 

[pashnit]

I read somewhere on here about using compressed air to shoot it out.

Which is how I cleaned all my screens inside the fuel pump.

 

[delbert]

mine was the same , used wd40 on it & kept playing with it . had to give it a fair ol tug but it gave up in the end with out damage

 

[woodlandtechie]

Hey the WD40 trick worked perfectly...gotta love liquid spanner!!!

However, I've just got the bike back together and it runs like a tractor, misfiring, stuttering and just wont rev...starts first time....which is good....but runs like a pig....

Checked the plugs which are new, cleaned & gapped, all conections present to the airbox...all sensors plugged in...no error codes, idles ok at first, stutters then stalls...does this sounds like fuel pressure? Did i get the hoses on the right connections to the tank I wonder, the manual is a little vague on this point.....

I was goint to use the bike tomorrow to go to work but looks like I'm on the train...bugger!!

 

[delbert]

you may have the hoses on wrong , some one on here posted some pics of them try a search , also check the hoses are not kinking when you lower the tank , thats a common one they get a bit soft

 

[delbert]

https://www.hayabusa.org/forum/busa...-line-routing.html?highlight=fuel+return+hose

there ya go , hope this helps

 

[woodlandtechie]

Ok, just nipped out to take a this piccy...think it's the same as the thread link picture..

Seems my hoses are a little shorter than standard, the previous owner must given them a trim at some point...

 

[delbert]

yea they look right . just make sure they are not getting kinked when you drop the tank , they can get a little soft were they bend , about all i can say at the mo

 

[woodlandtechie]

just make sure they are not getting kinked when you drop the tank , they can get a little soft were they bend

Agreed - I don't think they're kinking but it's possible, I think I'm going to replace them as a matter of course..on another note I think I've tracked the problem down to a failed IAP sensor...just waiting for the replacement sensor & vacuum hose to arrive.....

 

[delbert]

good luck , keep us posted

 

[dk55belair]

was your bike cutting out before you removed the fuel pump?

 

[woodlandtechie]

hey all still waiting for the map sensor to arrive so can't run the bike yet but the downtime has given some time to get some maintenance in after the winter....I hate road salt.......I'm sure there's a better alternative than salt available...

I think I'm going have a set of winter components to swap out with the good stuff in the waiting when the weather improves,...

Ok, back to the fuel pump issue.....yes....

was your bike cutting out before you removed the fuel pump?

Yes it was, it displayed some odd stuttering and misfiring when the fuel level got about a quarter tank, I once ran the bike until the fuel light came on and boy did the bike misbehave. I was on my way home and the misfiring started, I really struggled to keep the bike running.

Eventually I pulled on the the side of the road, and disconnected the PCII as I though this may have been going bad, anyway the bike restarted and ran fine for a few minutes then started to run worse than ever, in my attempted to keep the bike running I grabbed a full handful of throttle, the engine fired and I ended up in a huge power slide at about 60mph and accelerating on a busy, wet motorway.....I gotta say this was a change of underwear moment.......

So I got to a fuel station, brimmed the the tank and the bike ran fine....confused? damn confused...I put this down to crap in the fuel tank, so I stripped the pump out, cleaned the filters, washed the tank and fuel strainer out but didn't find, imho, enough residue or particulate to affect the running as it did...

So the pump screen was dirty on the lower half, the fuel pressure regulator screen was clear, the fuel filter was a little slimy but not as bad as I've seen in similar posts on Gen 2's, the injector screen were clear and no dirt in the injector rail as you would expect if the filter were doing their job.

My theory so far, is that when the fuel level get low, the pump is moving so much, it's possibly drawing in air with the fuel so cavitation is possible.

When I run the bike low in a straight line it's not so bad, in the twisties it's really bad. I guess in future the best option to to keep it above half full, easier said then does on long runs though...

 

[woodlandtechie]

Ok, I have the map sensor, not quire the correct plug fitment but after making a jumper harness the bike starts & idles...it's not right thought...I'm sure its a fuel pressure issue...if I hold the throttle steady say 6000 rpm...it surges, drops, stutters, surges again then almost stalls..

Guess I'm stripping the fuel pump again....

 

[delbert]

have you checked the tip over sensor under the tank mounting bracket , i heard they have a a habbit of the brackets cracking , causing chaos

wouldnt explain the full / half tank thingy though but might be worth a look

 

[dk55belair]

My started cutting out around 6k rpms, i tried several things and finally pulled the tank and swapped with Willies. The bike ran perfect, so i found my filter screen full of rust. I replaced it and cleaned the rust out, put it together and it is still cutting out.

I think the clogged screen ruined the fuel pump. I'm gonna replace the pump. will updated. Sounds like your problem and mine are similar.

Your pump could be cracked or something and sucking air when the fuel level drops below the crack or leaking area????

 

[woodlandtechie]

I stripped the pump out again this afternoon...I found the problem with low fuel pressure...

The 10mm OD stub from the pressure side of the pump has a sleeve, this is sealed inside the filter housing inlet with an O ring, this had moved and was blocking the fuel delivery tube. Made no difference at low revs but killed it at the higher fuel delivery rates...anyway, replaced with a new o ring, sealed the pump back up, the bike will rev but still runs like a complete dog...rich as hell...guess it's boned!!!

Now on the lookout for the correct IAP sensor and I think the TPS is flaky also...

 

[hayabusaboy]

I had the same problem on mine, but after I had stripped the pump. It turned out I had forgotten to refit the vacuum hose to the pump. This is on a 2000 with an external pump. Once refitted, she ran sweet

 

[woodlandtechie]

Yeah, I though I'd forgotten a vacuum hose at first so tore it all down again, that's when I found the errant o-ring. I've now replaced all of the vac tubing with new silicone piping while I had the chance.

I did but a replacement sensor but it was the wrong fitting so it needs to be returned. After hours of searching I found a map sensor here:

MAP Sensor Suzuki GSX1300 1999-05 - Motorcycle Products Ltd

Hopefully this should fix my problem and I can ride my bike again...