Engine Mechanical problem
1998 Isuzu Amigo 4 cyl Two Wheel Drive Manual 100000 miles

I replaced the fuel pressure regulator and it still has a problem starting. I have to turn the key over awhile before it catches. Like fuel isn't getting all the way up. When I drive there are no problems. After driving awhile it will start right up , but if it sits up awhile it takes time to start. What needs to be done ? Do I need to pressure up the fuel line where the F. P. R. sits in ? Or is there something else I should do to resolve this problem ? My # is 832 893 1246 if you would like to call.