Fuel Pump & Circuit Testing

FUEL PUMP EXPLODED VIEW




FUEL PUMP CIRCUIT
1. Check fuel pump operation:
(a) Turn the ignition switch to ON.

NOTE: Do not start the engine.




(b) Using SST (09843-18020). connect terminals FP and +B of the check connector.

NOTE: The check connector is located under the drivers seat.




(c) Check that there is pressure in the fuel inlet hose.

NOTE: At this time, you will hear fuel pressure noise.

(d) Remove SST from the check connector.
(e) Turn the ignition switch to OFF.
If there is no pressure, check the following parts.
- Fusible link
- Fuse
- EFI main relay
- Fuel pump
- Wiring connections

2. Check fuel pressure:
(a) Check that battery voltage is above 11 volts.
(b) Disconnect the battery negative (-) terminal.
(c) Remove the RH engine service hole cover.




(d) Place a suitable container or shop towel under delivery pie.
(e) Slowly loosen the union bolt of the fuel pipe and disconnect the fuel pipe from the delivery pipe.
(f) Drain the fuel from the delivery pipe.




(g) Install SST (09268-45012) to the delivery pipe with two new gaskets as shown in the illustration.
(h) Wipe off any splattered gasoline.




(i) Reconnect the battery negative (-) terminal.
(j) Using SST (09843-18020), connect terminals FP and +B of the check connector.




(k) Turn the ignition switch to ON.
(l) Measure the fuel pressure.

Fuel pressure: 2.7-3.1 kg/cm2 (38-44 psi, 265-304 kPa)

If high, replace the pressure regulator. If low, check the following parts:
- Fuel hoses and connection
- Fuel pump
- Fuel filter
- Pressure regulator

(m) Remove SST from the check connector.




(n) Start the engine and warm up the engine for at least 2 minutes.
Disconnect the vacuum hose from the pressure regulator and plug the hose end.
(p) Measure the fuel pressure at idle.

Fuel pressure: 2.7-3.1 kg/cm2 (38-44 psi, 265-304 kPa)




(q) Reconnect the vacuum hose to the pressure regulator.
(r) Measure the fuel pressure at idle.

Fuel pressure: 2.1-2.5 kg/cm2 (30-36 psi, 206-245 kPa)

If not within the specified pressure, check the vacuum hose and pressure regulator.




3. Inspect High-Temperature line pressure:
(a) Start the engine. Warm up the engine until the water temperature is 80°C (176°F) or more, then stop the engine.
(b) Restart the engine.
(c) Measure the fuel pressure.

Fuel pressure: 2.7-3.1 kg/cm2 (38-44 psi, 265-304 kPa)

If pressure is low, check the following parts:
- ECU
- Fuel pressure control VSV
- Water temperature sensor
- Wiring
- Measure the fuel pressure at idle two minutes later.

Fuel pressure: 2.1-2.5 kg/cm2 (30-36 psi, 206-245 kPa)

(d) Stop the engine. Check that the fuel pressure remains above 1.5 kg/cm2 (21 psi, 147 kPa) for 5 minutes after the engine is turned off. If not within specification, check the fuel pump, pressure regulator and/or injectors.
(e) After checking fuel pressure, disconnect the battery negative (-) terminal and carefully remove the SST to prevent gasoline from splashing.




(f) Using new gaskets, reconnect the fuel pipe to the delivery pipe.

Torque: 300 kg/cm (22 ft.lbs., 30 Nm)

(g) Start the engine and check for fuel leakage.