Fuel Pressure: Testing and Inspection

FUEL PUMP ON-VEHICLE INSPECTION

1. Check fuel pump operation.
(a) Remove the fuse cover on the instrument panel.





(b) Connect the LEXUS hand-held tester to the DCL 3.
(c) Turn the ignition switch ON and LEXUS hand-held tester main switch ON.

NOTICE: Do not start the engine.

(d) Select the active test mode on the LEXUS hand-held tester.

(e) Please refer to the LEXUS hand - held tester operator's manual for further details.

(f) If you have no LEXUS hand-held tester, connect the positive (+) and negative (-) leads from the battery to the fuel pump connector.





(g) 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 links
- Fuses
- EFI main relay
- Fuel pump
- ECM
- Wiring connections
(h) Turn the ignition switch OFF.
(i) Disconnect the LEXUS hand-held tester from the DCL 3.
(j) Reinstall the fuse cover on the instrument panel.
2. Check fuel pressure.
(a) Check the battery voltage is above 1 2 V.
(b) Disconnect the negative (-) terminal cable from the battery.





(c) Remove the union bolt and 2 gaskets, and disconnect the fuel inlet pipe from the delivery pipe.

CAUTION:
- Put a shop towel under the delivery pipe.
- Slowly loosen the union bolt.





(d) Install the fuel inlet pipe and SST (pressure gauge) to the delivery pipe with the 3 gaskets and SST (union and union bolt).
SST 09268-45012 (09268-41 190,90405-06167)

Torque: 29 N.m (300 kgf.cm, 22 ft.lbf)

(e) Wipe off any splattered gasoline.





(f) Connect the LEXUS hand-held tester to the DCL 3.

(See step 1 ((a) to (f)) above)

(g) Reconnect the negative (-) terminal cable to the battery.
(h) Turn the ignition switch ON.





(i) Measure the fuel pressure.

Fuel pressure: 265 - 304 kPa
(2.7 - 3.1 kgf/sq.cm, 38 - 44 psi)

- If pressure is high. replace the fuel pressure regulator.
- If pressure is low, check these parts:
- Fuel hoses and connections
- Fuel pump
- Fuel filter
- Fuel pressure regulator
(j) Remove the LEXUS hand-held tester from the DCL 3.
(k) Reinstall the fuse cover on the instrument panel.
(i) Start the engine.
(m) Disconnect the vacuum sensing hose from the fuel pressure regulator, and plug the hose end.
(n) Measure the fuel pressure at idle.

Fuel pressure: 265 - 304 kPa
(2.7 - 3.1 kgf/sq.cm, 38 - 44 psi)

(o) Reconnect the vacuum sensing hose to the fuel pressure regulator.
(p) Measure the fuel pressure at idle.

Fuel pressure: 206 - 255 kPa
(2.1 - 2.6 kgf/sq.cm, 31 - 37 psi)

- If pressure is not as specified, check the vacuum sensing hose and fuel pressure regulator.
(q) Stop the engine.
(r) Check that the fuel pressure remains as specified for 5 minutes after the engine has stopped.

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

- If pressure is not as specified, check the fuel pump, pressure regulator and/or injectors.
(s) After checking fuel pressure. disconnect the negative (-) terminal cable from the battery and carefully remove the SST to prevent gasoline from splashing.
SST 09268-45012
(t) Reconnect the fuel inlet pipe to the delivery pipe with 2 new gaskets and the union bolt.

Torque: 29 N.m (300 kgf.cm, 22 ft.lbf)

(u) Reconnect the negative (-) terminal cable to the battery.
(v) Check for fuel leaks.