Vapor lock with no return is solved as the electro-mechanical injector units open to allow fuel to travel through the system. Look for this to become an industry standard, because almost all OEMs are using at least one version of this system today. At the end of the rail is a pressure regulator designed to maintain a constant fuel pressure at the injector. Each injector has a 10-micron final basket filter to protect the injector. Excess fuel above the regulated volume, usually 50 to 80 percent, then is returned to the fuel tank.
Filtration varies from model to model and brand to brand.
Gerotor fuel pump strainer is 33 micron, which is much finer than the usual 70-micron filter. Test procedures differ very little from system to system. Automotive engineers have used the low-current probe for years to measure actual current of circuits and design features. Only recently have these probes become part of the automotive technician's toolbox. This is all done with an inductive hookup without disturbing the circuit.