I'm trying to determine if I have an actual problem. By following the service manual, the fuel pressure is 40 PSI (manual says it should be between 30-50 PSI) on the external gauge connected to the shraeder valve on the fuel rail with the ignition on but engine not running. The scan tool shows 40 PSI. When I start the car the fuel pressure on the external meter drops to 30 PSI at idle (manual says it should be between 27-37 PSI) but the scan tool still shows 40 PSI. Since the fuel pressures...

2002 Mustang GT fuel pressure