Thread: Starting problems due to fuelling

Hi, first suspect is the air bleed valve in the rear wheel side connection of the fuel filter head (WJN500110), quite common... after you replaced it run a purging sequence(5 throttles with ignition on II then wait untill the MIL stops flashing) if no joy with that i'm affraid you'll have to go for the injector copper washers... meanwhile put a new branded fuel filter anyway

I was thinking the injector seals, unfortunately not a job I can do myself for a fair while so I will have to tank it into the mechanics.
On another note, and I am unsure if this relates to the issue, but when I open my fuel cap I get a hissing noise of air being sucked in, I know its probably my vent hose blocked up but do you think this could cause the air in the fuel line issue?

I say again, the air bleed valve is the first suspect...it's a 5 min diy job, it has a quick release connector, remove the rubber dust cap from it, push the two tabs in, push forward slightly then pull and the fuel pipe will release, unscrew the old connetion with valve, screw in the new one and push the fitting back... the air in the tank has nothing to do with air in the fuel lines as long as you didnt run it dry

Originally Posted by sierrafery

I say again, the air bleed valve is the first suspect...it's a 5 min diy job, it has a quick release connector, remove the rubber dust cap from it, push the two tabs in, push forward slightly then pull and the fuel pipe will release, unscrew the old connetion with valve, screw in the new one and push the fitting back... the air in the tank has nothing to do with air in the fuel lines as long as you didnt run it dry

I did just give it a go pulling it out to have a look. The fuel line came off easy enough, but I couldnt unscrew the connection out of the filter assembly. Will try again tomorrow after hitting it with a bit of wd40.

Try to unscrew it after a run when the head is hot but just looking to it won't help cos it has an internal membrane which fails and you can't see that, get a new one before you unscrew it cos that's the only way to rule it out

Originally Posted by DESCRIPTION AND OPERATION 19-1-9

An air bleed valve is located in the bleed line connection. The valve comprises a restrictor and a membrane. The
restrictor has a small hole in its centre. This allows air and fuel to pass through the membrane. Air can pass through
the membrane, but once the membrane is wet with fuel it will not allow further fuel to pass through.

Cool thanks, I was hoping it could be a blockage or something like that. Ill order one now.

Even if you dont understand what they say the test shows what happens with the internals removed(like when the valve is fubar'd)
[ame]https://www.youtube.com/watch?v=noHx8XUhY2o[/ame]

As Sierrafery says, this is the first suspect to rule out. Next for me would be to make sure you don't have any other fuel leaks that could be leading to the fuel draining out (such as fuel pressure regulator) when parked up. Then I did have to replace the injector washers.

Meanwhile, all this dry running and bleeding of the fuel pump could not be good, and yes had to do the fuel pump not long afterwards,

So when you have sorted the problem out, make sure that when done the pump does not sound too loud. Fuel pump should hardly be noticeable when it is running normally. But as Sierrafery says, start with the simple stuff first.