Fuel Pressure: Testing and Inspection

FUEL PRESSURE AND FUEL PUMP SYSTEM CIRCUIT INSPECTION

Fuel Pump System Circuit Schematic:

1. Check fuel pump operation.




(a) Using Special Service Tool (SST) (09843-18020), connect terminals +B and FP of the data link connector 1 (DLC1).




(b) Turn the ignition switch ON.
NOTICE: Do not start the engine.




(c) 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 the following parts:
- Fusible link
- H-fuse
- Fuses
- EFI main relay
- Fuel pump
- Wiring connections




(d) Turn the ignition switch to LOCK.




(e) Remove the SST from the DLC1.




2. Check fuel pressure.
(a) Check that the battery voltage is above 12.0 Volts.
(b) Disconnect the negative (-) terminal cable from the battery.
CAUTION: Work must be started after 90 seconds from the time the ignition switch is turned to the LOCK position and the negative (-) terminal cable is disconnected from the battery.




(c) Remove the union bolt and 2 gaskets, and disconnect the fuel inlet hose from the fuel filter outlet.
CAUTION:
- Put a suitable container or shop rag under the fuel filter.
- Loosen the union bolt slowly.




(d) Install the fuel inlet hose and SST (pressure gauge) to the Fuel Filter with 3 new gaskets and union bolt (SST 09268-45012).
Torque: 29 Nm (22 ft lb)
(e) Wipe off any splattered gasoline.




(f) Using SST (09843-18020), connect terminals +B and FP of the DLC 1.
(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 (38 - 44 psi)
^ If pressure is high. replace the fuel pressure regulator. If pressure is low, check the following parts:
- Fuel hoses and connections
- Fuel pump
- Fuel filter
- Fuel pressure regulator




(j) Remove the SST from the DLC 1.




(k) Start the engine.
(I) Disconnect the vacuum sensing hose from the fuel pressure regulator and plug the hose end.




(m) Measure the fuel pressure at idle with the vacuum hose disconnected.
Fuel pressure: 265 - 304 kPa (38 - 44 psi)




(n) Reconnect the vacuum sensing hose to the fuel pressure regulator.




(o) Measure the fuel pressure at idle with the vacuum hose connected.
Fuel pressure: 206 - 255 kPa (31 - 37 psi)
^ If pressure is not as specified. check the vacuum sensing hose and fuel pressure regulator.




(p) Stop the engine.
(q) Check that the fuel pressure remains as specified for 5 minutes after the engine has stopped.
Fuel pressure: 147 kPa (21 psi) or more
^ If pressure is not as specified. check the fuel pump, pressure regulator and/or injector.
(r) After checking fuel pressure, disconnect the battery negative (-) cable carefully remove the SST to prevent gasoline from splashing.




(s) Reconnect the fuel inlet hose to the fuel filter with with 2 new gaskets and the union bolt.
Torque: 29 Nm (22 ft lb)
(t) Reconnect the negative (-) terminal cable to the battery.
(u) Check for fuel leaks.