DESCRIPTION & OPERATION
The fuel pump is a pin and roller type electric pump equipped with an integral relief valve. Internal components include a rotor, check valve, relief valve, and silencer. (Scheme 56) On all models, pump is located in fuel tank. Pump is not serviceable and must be replaced as a unit if defective.
Sectional View of Electric Fuel Pump. Scheme 56
Scheme 57
- Turn ignition switch on. On Cressida and MR2 models, insert jumper wire between terminals "Fp" and "+ B" of service connector. On all other models, install jumper wire between both terminals of fuel pump check connector. (Scheme 57) (Scheme 57): Grounding Connector To Test Fuel Pump
- Fuel pump check connector is near master cylinder on Pickup and 4Runner models, at right rear corner of engine compartment on Corolla GTS models and near airflow meter on Van and Celica Supra models.
- Check for pressure in hose to cold start injector. Check for fuel return noise from pressure regulator. If no pressure in hose to cold start injector, check the following: Circuit opening relay EFI fuse Fuel pump Fusible link Ignition fuse Wiring connections
Scheme 58
Scheme 59
- Ensure battery voltage is more than 12 volts. Disconnect negative battery cable. Disconnect wiring connector from cold start injector. Loosen the union bolt of cold start injector hose on fuel delivery pipe.
- With shop towel under delivery pipe fitting, remove the bolt and 2 gaskets from the delivery pipe. Drain fuel in delivery pipe. Install fuel pressure gauge. (Scheme 58)or (Scheme 59). Wipe off spilled fuel and reconnect negative battery cable. On Cressida and MR2 models, insert jumper wire between terminals "Fp" and "+ B" of service connector. On all other models, install jumper wire between both terminals of fuel pump check connector. (Scheme 57) Turn ignition on. (Scheme 58): Fuel Pressure Gauge Installation (Except Celica Supra)
- Fuel pump check connector is near master cylinder on Pickup and 4Runner models, at right rear corner of engine compartment on Corolla GTS models and near airflow meter on Van and Celica Supra models.
- Measure fuel pressure. Fuel pressure should be 33-38 psi (2.3-2.7 kg/cm 2 ). If pressure is high, replace pressure regulator. If pressure is low, check the following: Fuel filter Fuel hoses and connections Fuel pump Pressure regulator
- Remove jumper wire from service connector. Disconnect pressure regulator sensing hose. Start engine. With engine idling, fuel pressure should be about 33-38 psi (2.3-2.7 kg/cm 2 ).
- Reconnect pressure regulator sensing hose. Fuel pressure should drop to 27-31 (1.9-2.2 psi). If pressure does not change as specified, check vacuum sensing hose and pressure regulator.
- Turn ignition off. Verify fuel pressure remains more than 21 psi (1.5 kg/cm 2 for 5 minutes after engine is turned off. If pressure does not remain as specified, check fuel pump, pressure regulator, and/or injectors.
- After checking fuel pressure, disconnect negative battery cable and remove fuel pressure gauge. Using new gaskets, reinstall cold start injector hose to fuel delivery pipe. Reconnect cold start injector wiring connector. Check for fuel leaks.
Removal & Installation
- Disconnect negative battery cable. Drain fuel tank. Disconnect and label all lines at fuel tank. Remove fuel tank. Remove fuel pump bracket bolts from fuel tank. Pull out fuel pump bracket assembly.
- Remove 2 nuts and disconnect wiring from fuel pump. Pull fuel pump off lower end of bracket. Disconnect fuel hose from fuel pump. Remove rubber cushion and filter from fuel pump.
- To install, reverse removal procedure. Ensure rubber protectors are correctly installed on fuel tank before mounting tank in position.