Chrysler Repair: 88 New Yorker 3.0L No start: Fuel Pump?, chrysler new yorker, safety precaution

Question
I recently put a new fuel pump in an 88' Chrysler New Yorker (4-5 months ago). I started the car the other day to warm it up and after a few minutes it stalled and will not start. It has spark. It has a 1/2 tank of gas. I hear the pump initially come on so I removed the line right before the fuel filter, no gas pushing through. Is there a pressure relay or some type of switch that may have to be reset or replaced?

Answer
Hi Chuck,
I checked the wiring diagram and found nothing unusual about the fuel pump. It is powered right off the autoshutdown relay which also provides power to the spark coil, oxygen sensor, and injectors on a dark green/black wire. If you hear it run for a second or so, then that means the wire is connected, and it is running as it should (cuts out after a second if you don't start and continue to run the engine...as a safety precaution). So I wonder if you have pressure in the gas line. It could be the pressure regulator has worn out and is allowing the fuel to return directly to the tank. It is located on the fuel rail at the engine (3.0L). The pump might have failed too. The pressure should be 48 psi, and after a little bit of cranking when you soon go to open the outgoing line to the filter you should have found it to be under pressure. If not, then either the pump isn't putting out fuel under pressure or the pressure regulator is not maintaining it. You could check for pressure in the line between the tank and the filter using a gauge while you crank it. The fuel pump has two internal check valves: one regulates internal pump pressure and regulates maximum output, the other near the pump outlet prevents flow in either direction when the pump is not operating. The pressure is supposed to be maintained such that when you first service the system you are supposed to first open the injectors enough (by grounding the harness) to allow the fuel pressure to drop so you don't have fuel spraying around the engine compartment.
Because you have spark while you are cranking it (is it for a full 5 second test?) that means the sensors for the engine rotation are getting through to the PCM which powers up the ASD.  
Let me know if there is anything else you need.
Roland