Maintenance Manual for J2 Sedan
Electronic Control System
of Engine
178
■
During inspection of fuel pressure, always to make sure whether there is fuel leakage in fuel
pipeline.
7) If the measured fuel pressure is more than the standard value, analyze the possible reasons referring
the following table and repair as required.
Fuel System Trouble Diagnosis Table 1
Phenomenon
Possible Cause
Troubleshooting
Blockage of fuel filter
Replace the fuel filter
Too low fuel pressure
Damaged fuel pump or poor sealing of fuel pressure
regulator resulting in fuel leakage at returning side
Replace fuel pump
Cementation of fuel pressure
Replace fuel pump
Too high fuel pressure
Blockage or bend of fuel return pipe
Repair or replace fuel
pipe
8) Turn off engine and check the changes of fuel pressure gauge reading for 5min. If the reading drops,
observe the reduction rate. Referring to following table to analyze and eliminate the trouble.
Fuel System Trouble Diagnosis Table 2
Phenomenon
Possible Cause
Troubleshooting
Fuel pressure drops slowly after engine
stopped
Leakage of fuel injector
Replace injector
Fuel pressure drops completely after engine
stopped.
Trouble of fuel pump
Replace pump
9)
Reduce the pressure in fuel pipeline.
10) Disconnect the fuel pressure gauge and install the inspection port nut.
11) Check for fuel leakage with following steps.
①
Turn the ignition switch to the "ON" position (with engine stopped), and then check for leakage at
the joint of the fuel pipeline.
②
Start the engine and increase speed, inspect whether there is leakage at joint of fuel system.
