[Al Skierkiewicz]

My guy says the fuel pressure test is the telling diagnostic at this point. He asks if you depress the accelerator after it starts, will it continue to run? If you can keep it at 1500 to 2000 RPM then it points to something in the idle circuit. There is a pipe/hose that runs from the intake to the throttle body that feeds the MAS air flow sensor. That could be clogged or cracked or the sensor is defective. There is also a flap in the throttle body that supplies idle air that may have become dirty or stuck. It is able to be cleaned but it may take someone holding the throttle open while you use some carb cleaner on a brush to clean the plate and pivot. Don't spray into the throttle body. You may also have a IAC valve that is not working.
There is a wire that runs from the fuel pump relay on the front driver's side of the engine compartment across the front of the radiator and back into the passenger side of the car to the computer. This wire sometimes breaks,frays, goes intermittent.
Of course, if the pressure doesn't stay up during start and run, then it points to the fuel pump.