Fuel Pressure Regulator Test

If fuel pressure gauge is already attached, go to next step. If not, 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 Pressure 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 and No. 22 from 9000 models. 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 models. This will provide current to the fuel pump. Turn ignition on.
Line pressure should rise to approximately 36 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.
Remove pressure tester. Install vacuum pump to "Y" connection. Line pressure should be at approximately 36 psi (2.5 kg/cm² ). Use vacuum pump to create various test vacuums, and compare vacuum readings to specification. See APPLIED VACUUM REGULATOR SPECIFICATIONS table.
Turn ignition on to operate fuel pump. Verify fuel line pressure of 36 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.

APPLIED PRESSURE REGULATOR SPECIFICATIONS

Applied Pressure psi (kg/cm² )	Line Pressure psi (kg/cm² )
0 (0)	36.3 (2.5)
2.9 (.2)	39.2 (2.7)
5.8 (.4)	42.1 (2.9)
8.6 (.6)	44.9 (3.1)

APPLIED VACUUM REGULATOR SPECIFICATIONS

Applied Vacuum In. Hg	Line Pressure psi (kg/cm² )
0	36.3 (2.5)
5	33.4 (2.3)
11	30.5 (2.1)
16	27.5 (1.9)