Fuel Pressure Regulator Test
- If fuel pressure gauge is already attached, go to step 2). If fuel pressure gauge is not attached, disconnect banjo coupling at inlet to fuel injection manifold. Connect fuel pressure gauge at this point, using existing seals. Ensure pressure gauge hangs vertically.
- Connect Vacuum Gauge (83 93 514), with "Y" connection, to vacuum port of fuel pressure regulator. Hang pressure gauge vertically. Connect cooling system pressure tester to "Y" connection.
- Turn ignition off. Remove fuse No. 30 on 900 models. Remove fuse No. 14 from 9000 Turbo. Connect a jumper lead between fuse No. 27, 28, or 29 and slot of fuse No. 30 for 900 models. Connect the jumper between fuse No. 22 and slot of fuse No. 14 on 9000 Turbo. This will provide current to the fuel pump. Turn ignition on.
- Line pressure should rise to about 35.0 psi (2.5 kg/cm2
). Using a pressure tester, raise system pressure to various test pressures, and compare line pressure to specification. See APPLIED PRESSURE REGULATOR SPECIFICATIONS table.APPLIED PRESSURE REGULATOR SPECIFICATIONS
Applied Pressure: psi (kg/cm2 ) Line Pressure: psi (kg/cm2 ) 0 (0) 35.0 (2.5) 2.8 (.2) 37.8 (2.7) 5.6 (.4) 40.6 (2.9) 8.4 (.6) 43.4 (3.1) - Remove pressure tester. Install vacuum pump to "Y" connection. Line pressure should be about 35.0 psi (2.5 kg/cm2
). Use vacuum pump to create various test vacuums. Compare vacuum readings to specification. See APPLIED VACUUM REGULATOR SPECIFICATIONS table.APPLIED VACUUM REGULATOR SPECIFICATIONS
Applied Vacuum: In. Hg Line Pressure: psi (kg/cm2 ) 0 (0) 35.0 (2.5) -2.8 32.2 (2.3) -5.6 29.4 (2.1) -8.4 26.6 (1.9) - Turn ignition on to operate fuel pump. Verify line pressure of 35.0 psi (2.5 kg/cm2 ). Turn ignition off. Check pressure gauge reading. Pressure should drop 1.4-2.8 psi (.1-.2 kg/cm2 ), and then hold steady for at least 10 minutes.
- If pressure drops more than specified, check for leakage in pressure regulator and fuel pump non-return valve.