Fuel Pump: Testing and Inspection

1. CHECK FUEL PUMP OPERATION




a. Connect a LEXUS hand-held tester to the DLC3.
b. Turn the ignition switch ON, and push the LEXUS hand- held tester main switch ON.

NOTE: Do not start the engine.

c. Select the active test mode on the LEXUS hand-held tester.
d. Please refer to the LEXUS hand-held tester operator's manual for further details.
e. If you have no LEXUS hand-held tester, connect the positive (+) and negative (-) leads from the battery to the fuel pump connector. (See step 3)




f. Check that there is pressure in the fuel inlet hose from the fuel filter.

HINT: If there is fuel pressure, you will hear the sound of fuel flowing. If there is no pressure, check these parts:
- Fusible link
- Fuses
- EFI main relay
- Fuel pump
- ECM
- Wiring connections

g. Turn the ignition switch OFF.
h. Disconnect the LEXUS hand-held tester from the DLC3.

2. CHECK FUEL PRESSURE
a. Check the battery positive voltage is above 12 V.
b. Disconnect the negative (-) terminal cable from the battery.
c. Remove the fuel pressure pulsation damper from the RH delivery pipe.




d. Install the rear fuel pipe and SST (pressure gauge) to the delivery pipe with 3 lower gaskets and SST (union bolt).
SST 092688-4501 4 (09268-41190, 90405-06167)

Torque: 39 Nm (400 kg.cm, 29 ft.lb)

e. Wipe off any splattered gasoline.
f. Reconnect the negative (-) terminal cable to the battery.
g. Connect a LEXUS hand-held tester to the DLC3. (See step 1 in check fuel pump operation (a) to (e))
h. Measure the fuel pressure.

Fuel pressure: 304 - 343 kPa (3.1 - 3.5 kg/sq.cm, 44 - 50 psi)

If pressure is high, replace the fuel pressure regulator.
If pressure is low, check these pants:
- Fuel hoses and connections
- Fuel pump
- Fuel filter
- Fuel pressure regulator

i. Disconnect the LEXUS hand-held tester from the DLC3.
j. Start the engine.
k. Measure the fuel pressure at idle.

Fuel pressure: 304 - 343 kPa (3.1 - 3.5 kg/sq.cm, 44 - 50 psi)

l. Stop the engine.
m. Check that the fuel pressure remains as specified for 5 minutes after the engine has stopped.

Fuel pressure: 147 kPa (1.5 kg/sq.cm, 21 psi) or more

If pressure is not as specified, check the fuel pump, pressure regulator and/or injectors.

n. After checking fuel pressure, disconnect the negative (-) terminal cable from the battery and carefully remove the SST to prevent gasoline from splashing.
SST 09268-05014
o. Reinstall the fuel pressure pulsation damper to the RH delivery pipe.
p. Reconnect the negative (-) terminal cable to the battery.
q. Check for fuel leaks.

3. INSPECT FUEL PUMP
a. Remove the rear seat cushion.
b. Remove the 3 cap nuts and floor service hole cover.
c. Disconnect the fuel pump & sender gauge connector.




d. Using an ohmmeter, measure the resistance between terminals 4 and 5.

Resistance: 0.2 - 3.0 Ohms at 20 °C (68 °F)

If the resistance is not as specified, replace the fuel pump.




e. Inspect the fuel pump operation.
Connect the positive (+) lead from the battery to terminal 4 of the connector, and the negative (-) lead to terminal 5. Check that the fuel pump operates.

NOTE:
- These tests must be done quickly (within 10 seconds) to prevent the coil burning out.
- Keep the fuel pump as far away from the battery as possible.
- Always do the switching at the battery side.

If operation is not as specified, replace the fuel pump.

f. Reconnect the fuel pump & sender gauge connector.
g. Reinstall the floor service hole cover with the cap nuts.
h. Reinstall the rear seat cushion.