Easy way is with a fuel pressure guage. Measure the pressure before the regulator and the pressure after and there should be a drop after the regulator. It doesn't regulate flow. It maintains the pressure in the fuel rail to keep the injectors spraying the right amount of fuel.

Maybe it's not the fuel. A missing vacuum line will give you the same problem and it's not going to fire if the air intake on the throttle body is disconnected.

'89 P'up, 2.6 I-Tec, 488,000 miles and done... gone to the great beyond