Fuel Pressure Regulator Check

1. Stop engine and disconnect fuel pressure regulator vacuum hose from intake manifold.
Fig 1: Plug Intake Manifold
Courtesy of NISSAN MOTOR CO., U.S.A.
2. Plug intake manifold with a blind cap.
3. Connect variable vacuum source to fuel pressure regulator.
4. Start engine and read indication of fuel pressure gauge as vacuum is changed.
   1. Fuel pressure should decrease as vacuum increases. If results are unsatisfactory, replace fuel pressure regulator. 

Fig 2: Reading Indication Of Fuel Pressure Gauge

Courtesy of NISSAN MOTOR CO., U.S.A.