Fuel Pump Control Circuit

FUEL PUMP SYSTEM CIRCUIT






ON-VEHICLE INSPECTION






1. CHECK FUEL PUMP OPERATION
a. Using SST, connect terminals +B and FP of the data link connector 1.
SST 09843-18020
b. Turn the ignition switch ON.

NOTICE: Do not start the engine.





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

HINT: At this time, you will hear fuel return noise.





d. Remove SST. SST 09843-18020
e. Turn the ignition switch OFF.
If there is no pressure, check the following parts:
^ Fusible link
^ Fuses AM2 30A. EFI ISA, IGN 7.5A
^ SF1 main relay
^ Fuel pump
^ FCM
^ Wiring connections

2. CHECK FUEL PRESSURE
a. Check that the battery voltage is above 12 volts.
b. Disconnect the cable from the negative - terminal of the battery.

CAUTION w / Airbag: Work must be started after approx. 30 seconds or longer from the time the ignition switch is turned to the LOCK - position and the negative - terminal cable is disconnected from the battery.





c. Disconnect the cold start injector connector.
d. Put a suitable container or shop towel under the cold start injector pipe No.2 fuel pipe.
e. Remove the union bolt and two gaskets, and disconnect the cold start injector pipe from the cold start injector.

HINT: Slowly loosen the union bolt.





f. Install SST pressure gauge to the cold start injector with three new gaskets and the union bolt.
SST 09268-45012
Torque: 15 Nm 150 kgf.cm, 11 ft.lb

g. Wipe off any splattered gasoline.





h. Using SST, connect terminals +B and FP of the data link connector 1.
SST 09843-18020

i. Reconnect the battery negative - cable.





j. Turn the ignition switch ON.
k. Measure the fuel pressure.
Fuel pressure: 265-304 kPa 2.7-3.1 kgf/cm2, 38-44 psi
If pressure is high, replace the fuel pressure regulator.
If pressure is low, check the following parts:
^ Fuel hoses and connection
^ Fuel pump
^ Fuel filter
^ Fuel pressure regulator
^ Injector





i. Remove SST.
SST 09843-18020





m. Start the engine.
n. Disconnect the vacuum sensing hose from the fuel pressure regulator, and plug the hose end.
o. Measure the fuel pressure at idling.
Fuel pressure: 265-304 kPa 2.7-3.1 kgf/cm2, 38-44 psi





p. Reconnect the vacuum sensing hose to the fuel pressure regulator.
q. Measure the fuel pressure at idling.
Fuel pressure: 226-265 kPa 2.3-2.6 kgf/cm2, 33-37 psi
If pressure is not as specified, check the vacuum sensing hose and fuel pressure regulator.

r. Stop the engine. Check that the fuel pressure remains 147 kPa 1.5 kgf/cm2, 21 psi or more for 5 minutes after the engine is turned off.
If pressure is not as specified, check the fuel pump, pressure regulator and/or injector.





s. After checking fuel pressure, disconnect the battery negative - cable and carefully remove the SST to prevent gasoline from splashing.
SST 09268-45012

t. Connect the cold start injector pipe No.2 fuel pipe with two new gaskets and the union bolt.
Torque: 15 Nm 150 kgf.cm, 11 ft.lb.

u. Reconnect the cold start injector connector.
v. Reconnect the cable to the negative - terminal of the battery.
w. Check for fuel leakage.