do returnless fuel-injected engines require the fuel tank to be pressurized/vacuum to run correctly? im thinking no, but can anyone else explain?

we are having problems with our motorcycle engine, the fuel pressure is only 5psi, and one of our teamates says its because or gas tank is leaking and causing low fuel pressure...what are your thoughts?

 

I think its just a pump malfunction.
...its a motorcycle with injection, not carbs?

 

yeah the yamaha fz600 engine is fuel injected