Checking Fuel Supply Pressure

Fig. 14 Fuel supply pressure regulator. Cross sectional view:

Fig. 15 Removing piston with wooden peg:

Fig. 16 Transfer valve assembly:

1. Close tap.
2. Pressurize fuel system with test harness.
3. Pressure should read 65.4 to 75.4 psi.
4. If fuel pressure is below 65.4 psi, check fuel pump output:
a. Remove return hose and install in its place hose 8.0141 E.
b. Using a graduated burette to measure pump output, activate switch on test harness for 30 seconds. Minimum output is 750cc.
c. If pump output is correct, check supply pressure regulator.
d. If pump output is too low, check fuel supply circuit for the following: pinched hoses or kinked lines, leaks, clogged filter, defective power supply to pumps, or air entry into fuel circuit between main pump and fuel tank.
5. If fuel pump supply pressure is above 75.4 psi, check supply pressure regulator and fuel return circuit to reservoir (pinched hose, kinked pipe). Check supply pressure regulator as follows:
a. Drain fuel from metering distributor.
b. Remove cap nut (1), Fig. 14 and save adjusting shims (2).
c. Remove spring (3) and piston (4) using wooden peg (5), Fig. 15.
d. Remove cap nut (7), push spring stop (8), towards right and remove circlip (9), Fig. 16.
e. Remove transfer valve (6) and check condition of O-rings (10). Replace if necessary.