TIBURON(GK) >2003 > G 2.0 DOHC > Fuel System > Fuel Delivery System > Fuel Pump>Repair procedures  
FUEL PUMP OPERATION CHECK
1.
Turn the ignition switch OFF.
2.
Using the Hi-scan(Pro)'s actuator test mode for fuel pump, check that pump operation.
The fuel pump is an in-tank type and its operation is hard to hear without removing the fuel tank cap.
3.
Pinch the hose to check that fuel pressure is felt.

FUEL PRESSURE TEST
1.
Press the two tabs under the rear seat and raise the seat, then detach the inspection panel of the fuel pump.
2.
To reduce the internal pressure of the fuel lines and hoses, first start the engine with the fuel pump disconnected and wait until it stops by itself.
Be sure to reduce the fuel pressure before disconnecting the fuel main pipe and hose, otherwise fuel will spill out.

3.
Disconnect the battery negative (-) terminal and then connect the fuel pump harness connector.
4.
Using the fuel pressure gauge, adaptor and connector, install the fuel-pressure gauge to the fuel delivery pipe. Tighten the bolt to the specified torque.


Tightening Torque
Fuel pressure gauge to fuel delivery pipe:
25 - 35Nm (250 - 350 kg.cm, 18 - 26 lb.ft)

5.
Connect the battery's negative (-) terminal.
6.
Apply battery voltage to the terminal for the pump drive and activate the fuel pump. Then, with fuel pressure applied, check that there is no fuel leak from the pressure gauge or connections.
7.
Start the engine and let it idle.
8.
Measure the fuel pressure.

Standard value : 350 kPa (3.5 kg/cm², 49.8 psi)

9.
If the result of the measurements made in steps (7) and (8) are not within the standard value, use the table below to determine the probable cause, and perform the necessary repairs.
Condition
Probable cause
Remedy
Fuel pressure too low
1)
Clogged fuel filter.
2)
Fuel leak on the fuel-pressure regulator that is assembled on fuel pump, caused by poor seating of the fuel-pressure regulator.
1)
Replace fuel filter.
2)
Repair the leak or replace the fuel pump.
Fuel pressure too high
1)
Sticking fuel-pressure regulator.
1)
Repair the leak or replace the fuel pump.

10.
Stop the engine and check for a change in the fuel pressure gauge reading, which should hold for approximately 5 minutes. If the gauge indication drops, observe the rate of drop. Determine and correct the causes according to the following table.
Condition
Probable cause
Remedy
Fuel pressure drops slowly after engine is stopped
1)
Injector leak
1)
Replace injector
Fuel pressure drops immediately after engine is stopped
1)
The check valve within the fuel pump is open
1)
Replace fuel pump

11.
Release the pressure in the fuel line.
12.
Disconnect the hose and the gauge.
Cover the hose connection with a shop towel to prevent splashing of fuel caused by residual fuel pressure in the fuel line.
13.
Replace the O-ring at the end of the hose.
14.
Connect the fuel hose to the delivery pipe and tighten to the specified torque.
15.
Check for fuel leaks.
FUEL FILTER REPLACEMENT
1.
Reduce the internal pressure of the fuel lines and hoses by completing the following operations.
A.
After removing the rear seat cushion, disconnect the fuel pump harness.
B.
Start the engine. Allow it to stop by itself, then turn the ignition switch OFF.
C.
Disconnect the battery negative (-) terminal.
D.
Connect the fuel pump harness connector.

2.
Remove the eye bolts while holding the fuel filter nuts securely.
Cover the fuel filter with a shop towel to avoid residual gasoline from splashing.
3.
Remove the fuel filter mounting bolts, then remove the fuel filter from the fuel filter clamp.
4.
After replacing the fuel filter, check for fuel leaks.

FUEL SENDER REPLACEMENT
1.
Remove the fuel tank cap to lower the fuel tank's internal pressure.
2.
Remove the fuel sender mounting screws, then remove the fuel sender from the fuel tank.