Fuel Pressure: Testing and Inspection

FUEL PRESSURE TESTING
Preparation
1. Reduce the internal pressure of the fuel pipes and hoses.



2. Remove the intake manifold plenum.
3. Disconnect the high pressure fuel hose at the fuel rail side.

CAUTION: Cover the hose connection with a shop towel to prevent splashing of fuel that could be caused by some residual pressure in the fuel pipe line.




4. Connect a fuel pressure gauge to the special tool, placing an adequate 0-ring or gasket between the gauge end special tool to prevent fuel leaks.




5. Attach the special tool which was connected in step (4) to the fuel rail.

Testing the Fuel Pressure - Engine Running



1. Connect a jumper wire to the terminal for activation of the fuel pump and to the positive battery terminal to activate the fuel pump. With fuel pressure applied, check that there is no fuel leakage from the fuel pressure gauge and the special tool connection part.
2. Measure the fuel pressure.

Standard value: 330-370 kPa (47-53 psi) at curb idle speed




If the fuel pressure measured in step (2) is outside the standard value range, check for the probable cause by referring to the table above, and then make the appropriate repair.

Testing the Fuel Pressure Leakdown - Engine Off



Disconnect the lead wire from the fuel pump activation terminal (black) to stop the fuel pump, and then check for a change of the value indicated by the fuel pressure gauge. The condition is normal if there is no decrease in the indicated value within two minutes. If there is a decrease in the indicated value, monitor the speed of the decrease, referring to the table above, determine the cause of the problem and make the appropriate repair.

Restoring the Fuel System to Pre-Test Condition
1. Connect a vacuum pump to the fuel pressure regulator and apply 80 kPa (600 mm Hg) of negative pressure to remove the residual pressure inside the fuel pipe line.
2. Disconnect the fuel pressure gauge and the special tool from the fuel rail.

CAUTION: Because there will be some residual pressure in the fuel pipe line, use a shop towel to cover so that fuel doesn't splatter.

3. Replace the 0-ring at the end of the high-pressure fuel hose with a new one.
4. After connecting the high-pressure fuel hose to the fuel rail, tighten the installation bolt to the specified torque.

Tightening torque: 5 Nm (3.6 ft.lbs)

5. Apply battery positive voltage to the terminal for activation of the fuel pump so as to activate the fuel pump.
6. With fuel pressure-applied, check for leakage of the fuel line.
7. Install the intake manifold plenum.