Fuel system not holding pressure

[rob702]

Whilst I am waiting for my pump to be delivered from the states I thought I would try putting a fuel pressure gauge on my old pump, my bike is an 05 when I turn the ignition on the pump came on for a few seconds and the pressure went up to 45 pounds but as soon the pump stopped the pressure dropped to zero instantly is this right ? or should it hold some pressure. If I start the bike up the pressure goes to 45 pound and stays there also when I took the fuel pipe off the tank /pump the fuel keeps flowing out and does not stop I am sure last time I took the tank off there was just a few drops of fuel then it stopped

Thanks for any help Rob

 

[07busa07]

If ur turning the key and the pump is priming then yes ur gauge will jump to where it's suppose too. After it's primed (bike not running) then yes it will drop because there is nothing to keep the fuel flowing. Once u start it ur pump injectors and a/f is pushing it through so it will go back up.

 

[rob702]

Thanks for your reply the reason I asked the question is when looking on the web for injector pump problems they all say you have a fault if the system is not holding pressure when turned on or off , which makes sense as on my bike once the pump has stopped the pressure drops to zero instantly so when I press the starter there is no pressure in the system and surely the reason the pump runs for a few seconds when the bike is turned on is to pressurise the system before you start it
Thanks Rob

 

[07busa07]

Yea when u turn the key to on position an have ur engine switch on ur pump primes the fuel system. I must of misread but u did say when u start it the pressure goes back up correct? It looks like according to ur original post ur just concerned with the pressure dropping after the pump primes?

 

[rob702]

Thanks for your reply yes I am just concerned with the pressure dropping after the pump primes as most systems hold pressure even when turn off for a short time, maybe the hayabusa doesn’t
Thanks Rob