http://users.vnet.net/w123d/w123d/injectiontiming.htm

Who ARE those people ?
Did they manufacture millions of Mercedes Benz ?
Did they have million dollar R and D departments which decided the million dollar Mercedes designers got it wrong ?

How can one expect EYEBALLING the WELLING UP can come close to matching seeing one drop at a time....and timing those drops ?

I also think you need to put a fuel can a few feet above the pump in order to have the steady pressure for the time it takes to move the pump. Using the hand pump only provides a decreasing pressure as you open up and try to adjust the position of the pump body....

What would you attach the rubber line to to use it instead of the metal bent tube ? and in curving it one would have to be sure not to crimp it doing such a sharp bend....