Whenever you open a pressurized fuel system you must purge line by turning ignition key to the on position for 10 secs +/- (you should hear pump kick on and stop). Then turn key back to the off position for another 10secs and then try to start. If air is present in line the pump won't pick up fuel. If that's the case crack open fuel line at the filter by turning nut on metal fuel line closest to the engine. The fuel filter is located underneath along frame rail. With the system open, turn on key until fuel has a steady flow then tighten nut while fuel is flowing . Similar to how you would bleed brakes.