Engine Performance problem
2001 Lincoln LS V8 Two Wheel Drive Automatic 131000 miles

I replace #5 fuel injector that was leaking,my fuel pressure was 30 pounds and it was idling bad,now it idle great but my fuel pressure is 33 pounds,it call for 35 to 65 pounds at idle,the fuel pressure gauge was unestable before I change the injector,it is ok now but only 33 ponds,the car is running and idling good,do I need to change the fuel pump? or it is ok to run it this way.
Any suggestion will be appreciated.
Manny