Turn the ignition SW ON. The fuel pump will turn for 3
seconds, and then stop.
Measure the fuel pressure with the engine stopped.
right after Ignition SW ON, with pump running:
after 3 seconds from Ignition SW ON,
with pump stopped:
Start the engine, and let it idle.
Measure the fuel pressure with the engine idling.
Fuel Pressure (idling)
260 kPa (2.7 kgf/cm², 38 psi)
Measure the fuel pressure with the throttle fully opened a
Fuel Pressure (with throttle fully opened)
The gauge needle will fluctuate. Read the pressure at
the average of the maximum and minimum indications.
If the fuel pressure is normal, the fuel circulation system
(fuel pump, pressure regulator, and oil passage) is no
faults. Check the DFI electronic control system (injectors,
sensors, crankshaft sensors, and ECU).
If the fuel pressure is much higher than the specified,
check the following:
Fuel Return Hose for Sharp Bend, Kinking, or Clogging
Return Fuel Check Valve (see Fuel Tank section in this
If the fuel pressure is much lower than specified, check
Fuel Pump for Operation (check the sound of the pump)
Fuel Line Leakage or Clogging
Amount of Fuel Flow (see Fuel Flow Rate Inspection)
If the fuel pressure is much lower than specified, and if
inspection above checks out good, replace the pressure
regulator, or the fuel pump assy (the fuel filter may be
clogged) and measure the fuel pressure again.
If the residual pressure 260
the high pressure fuel line could be leaking, including the
residual pressure check valve in the fuel pump.
Remove the fuel pressure gauge and adapter.
Run the fuel hoses in accordance with the Cable, Wire,
and Hose Routing section in the Appendix chapter.
310 kPa (3.2 kgf/cm², 46 psi)
280 kPa (2.9 kgf/cm², 41 psi,
residual fuel pressure)
The system should hold the residual
pressure about 30 seconds.
280 kPa (2.7
2.9 kgf/cm², 38
280 kPa drops at once,
FUEL SYSTEM (DFI) 3-89