On-Vehicle Inspection

WARNING: This page is about a different car, the 2004 Lexus SC 430, 2003 Lexus SC 430, and 2002 Lexus SC 430. However, it is still accessible from the selected car via links, so may be relevant.

CHECK FUEL PUMP OPERATION
1. Connect the LEXUS hand-held tester to the DLC3.
2. Turn the ignition switch ON and LEXUS hand-held tester main switch ON.
  NOTE: Do not start the engine.
3. Select the active test mode on the LEXUS hand-held tester.
4. Please refer to the LEXUS hand-held tester operator's manual for further details.
5. If you have no LEXUS hand-held tester, connect the positive (+) lead form the battery to terminal 4 of the connector, and the negative (-) lead to terminal 5.
CHECK FUEL PRESSURE
1. Check the battery positive voltage is above 12 V.
2. Disconnect the negative (-) terminal cable from the battery.
3. Remove the fuel pressure pulsation damper from the RH delivery pipe (See REPLACEMENT ).
  
  Fig 1: Connecting Positive (+) Lead Form Battery To Terminal 4 Of Connector & Negative (-) Lead To Terminal 5
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
4. Install the rear fuel pipe and SST (pressure gauge) to the delivery pipe with 3 lower gaskets and SST (union bolt).
  SST 09268-45014 (09268-41190, 90405-06167)
  
  Torque: 39 N.m (400 kgf.cm, 29 ft.lbf)
5. Wipe off any splattered gasoline.
6. Reconnect the negative (-) terminal cable to the battery.
7. Connect a LEXUS hand-held tester to the DLC3. (See step 1 in check fuel pump operation (a) to (e))
8. Measure the fuel pressure.
  
  Fig 2: Installing Rear Fuel Pipe & SST (Pressure Gauge) To Delivery Pipe With Lower Gaskets & SST (Union Bolt)
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Fuel pressure:
  
  304 - 343 kPa (3.1 - 3.5 kgf/cm ² , 44 - 50 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
9. Disconnect the LEXUS hand-held tester from the DLC3.
10. Start the engine.
11. Measure the fuel pressure at idle.
  Fuel pressure:
  
  304 - 343 kPa (3.1 - 3.5 kgf/cm ² , 44 - 50 psi)
12. Stop the engine.
13. Check that the fuel pressure remains as specified for 5 minutes after the engine has stopped.
  Fuel pressure: 147 kPa (1.5 kgf/cm ² , 21 psi) or more
  
  If pressure is not as specified, check the fuel pump, pressure regulator and/or injectors.
14. After checking fuel pressure, disconnect the negative (-) terminal cable from the battery and carefully remove the SST to prevent gasoline from splashing.
  SST 09268-45014
15. Reinstall the fuel pressure pulsation damper to the RH delivery pipe (See REPLACEMENT ).
16. Reconnect the negative (-) terminal cable to the battery.
17. Check for fuel leaks.