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 91) 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 91
Scheme 92
- Turn ignition switch on. On Cressida and MR2 models, insert jumper wire between terminals "Fp" and "+ B" of service connector. On all other models, short both terminals of fuel pump check connector. (Scheme 92) (Scheme 92): 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 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: Fusible link, EFI fuse, EFI main relay, ignition fuse, circuit opening relay, wiring connections, and fuel pump.
Scheme 93
- Disconnect negative battery cable. Unplug wiring connector from cold start injector. Loosen the union bolt of cold start injector hose on fuel delivery pipe.
- Remove the bolt and 2 gaskets from the delivery pipe. Drain fuel in delivery pipe. Install fuel pressure gauge. (Scheme 93) Wipe off spilled fuel and connect battery cable. Start engine. Disconnect and plug fuel pressure regulator vacuum hose. (Scheme 93): Fuel Pressure Gauge Installation
- With engine idling, 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 fuel system for leaks.
- Connect pressure regulator sensing hose. With engine idling, fuel pressure should be about 28 psi (2.0 kg/cm 2 ). If pressure is high, replace pressure regulator.
- Turn ignition off. If pressure drops quickly, check fuel pump, pressure regulator, and/or injectors. Remove pressure gauge. Using new gaskets, install removed parts.
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.