Fuel Pressure: Testing and Inspection
FUEL PRESSURE TEST1. Release residual pressure from the fuel line to prevent fuel spray.
2. Disconnect the fuel high pressure hose at the fuel rail side.
CAUTION: Cover the hose connection with rags to prevent splash of fuel that could be caused by some residual pressure in the fuel pipe line.
3. Remove the union joint and bolt from the special tool (adapter hose MD998709) and instead attach the special tool (hose adapter MD998742) to the adapter hose.
4. Install a fuel pressure gauge on the adapter hose that was set up in step 3.
Use a suitable O-ring or gasket between the fuel pressure gauge and the special tool so as to seal in order to prevent fuel leakage at this time.
5. Install the special tool, which was assembled in steps 3 and 4 between the fuel rail and the high pressure hose.
6. Use the scan tool to operate the fuel pump. Check the connections between the fuel pressure gauge and the special tool for leaks.
7. Start the engine and run at idle.
8. Measure fuel pressure while the engine is running at idle.
Standard value: Approx. 270 kPa (38 psi) at curb idle
9. Disconnect and plug the vacuum hose from the fuel pressure regulator and measure fuel pressure with the hose end closed by a finger.
Standard value: 330 - 350 kPa (47 - 50 psi) at curb idle
10. Check to see that fuel pressure at idle does not drop even after the engine has been raced several times.
11. Racing the engine repeatedly, hold the fuel return hose lightly with fingers to feel that fuel pressure is present in the return hose.
NOTE: If the fuel flow rate is low there will be no fuel pressure in the return hose.
12. If any of fuel pressure measured in steps 8 to 11 is out of specification, troubleshoot and repair according to the table.
13. Stop the engine and observe fuel pressure gauge reading. Normal if the reading does not drop within 2 minutes. If it does, observe the rate of drop and troubleshoot and repair according to the table.
14. Release residual pressure from the fuel pipe line.
15. Remove the fuel pressure gauge and special tool from the fuel rail.
CAUTION: Cover the hose connection with rags to prevent splash of fuel that could be caused by some residual pressure in the fuel pipe line.
16. Replace the O-ring at the end of the fuel high pressure hose with a new one.
17. Fit the fuel high pressure hose into the fuel rail and tighten the bolts to specified torque.
Tightening torque: 5 Nm (3.6 ft.lbs.)
18. Check for fuel leaks.
1. Use the scan tool to operate the fuel pump.
2. Check the fuel line for leaks, repair as needed.