I'm helping a buddy with his '93 5.0 mustang. The car wil start but will not stay idling. if the accelerator is gunned, it will run. The car has been tuned up (cap, rotor, plugs, air & fuel filter, also oil and filter). We thought maybe the fuel was old as it had been sitting for a few months so we drained out the old fuel and put in some fresh gas...Still the same issue. Got ahold of a fuel pressure tester from the loaner program at Autozone. The guy behind the counter looked up the spec and said it should be between 35 and 40 PSI. After putting the guage on the Mustang, we got a reading of 30 PSI. Would this reading cause the current issue? Is a new fuel pump in this car's future?