Fuel Pressure Test

(1) Reduce the internal pressure of the fuel pipes and hoses.
(2) Remove the fuel pressure regulator at the fuel rail side.

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





(3) Connect a fuel pressure gage to the special tool, placing an adequate O-ring or gasket between the gage end special tool prevent fuel leaks.
(4) After carrying out step (3), install the special tool between the fuel rail and the fuel pressure regulator.





(5) 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 gage and the special tool connection part.
(6) Disconnect the jumper wire from the terminal for activation of the fuel pump to stop the fuel pump.
(7) Start the engine and let it idle.
(8) Measure the fuel pressure during idling.

Standard value: Approx. 270 kPa (38 psi) at curb idle





(9) Disconnect the vacuum hose (blue stripe) from the air intake fitting manifold and then plug the nipple.
Measure the fuel pressure in this condition.

Standard value: 330-350 kPa (47-50 psi) at curb idle speed

(10) Check that the fuel pressure during idling does not decrease even after the engine is raced a few times.
(11) Use a finger to gently press the fuel return hose while repeatedly racing the engine, and check that there is fuel pressure in the return hose also.

NOTE: There will be no fuel pressure in the return hose if there is insufficient fuel flow.

(12) If the fuel pressure measured in steps (9) to (12) is outside the standard value range, check for the probable cause by referring to the following table and then make the appropriate repair.





(13) Stop the engine and check for a change of the value indicated by the fuel pressure gage. 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, and, referring to the following table, determine the cause of the problem and make the appropriate repair.
(14) Reduce the internal pressure of the fuel pipes and hose. Refer to Fuel Delivery and Air Induction/Fuel Pressure Release/Service and Repair.
(15) Disconnect the fuel pressure gage 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.

(16) Replace the O-ring at the end of the high-pressure fuel hose with a new one.
(17) 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)

(18) Check that there is no fuel leakage.
(1) Apply battery positive voltage to the terminal for activation of the fuel pump so as to activate the fuel. pump.
(2) With fuel pressure applied, check for leakage of the fuel line.