Residual Pressure

NOTE: Perform pressure tests in the following order:
1. System Pressure Test.
2. Residual Pressure Test.

RESIDUAL PRESSURE TEST

1. Initial setup:
a. Engine at operating temp.
b. Pressure gauge installed and bled of all trapped air.
c. Valve in open position.
d. Control pressure within specification -- 3.4 - 3.8 bar (49 - 55 psi).
2. Shut engine off.
3. Gauge readings should be:
a. after 10 minutes -- 2.6 bar (38 psi)
b. after 20 minutes -- 2.4 bar (35 psi)
4. If system does not hold adequate pressure, check:
a. Fuel pump check valve (located in the end of the fuel pump)
b. Fuel accumulator (look for fuel seeping from the vent)
c. Air filter for signs of leaking from the fuel distributor
d. Fuel pressure regulating valve
e. Cold start valve
f. Fuel lines for leaks
g. Frequency valve