Checking the main injection relay
A. There must be a circuit between the terminals
B. Gap
1. Two relays are included in the electrical circuit of the fuel system - the EFI relay and the pump relay. The EFI relay is mounted in the relay box in the engine compartment, the pump relay is located under the front panel. Check for battery voltage first at the main relay and then at the fuel pump relay.
2. Disconnect the main relay from the connector, then turn on the ignition (do not start the engine) and check for battery voltage at the connection point.
3. If there is battery voltage, replace the main relay and check for battery voltage at the fuel pump relay.
4. If battery voltage is present at both relays, check the relays themselves.
Main EFI relay
1. Use an ohmmeter to check for continuity between terminals 1 and 2 and 3 and 4.
2. Apply battery voltage to pins 1 and 2. Now there should be a closed circuit between pins 3 and 4. If the test results differ, replace the relay.
Checking the fuel pump relay
Fuel pump relay location on Toyota 4 Runner/ Hilux/ Surf
Checking the fuel pump relay
A. There must be a circuit between these pins
B. Gap
1. Using an ohmmeter, check the continuity of the circuit between the contacts according to the diagram.
2. Apply battery voltage to pins 1 and 2. There should now be a closed circuit between pins 3 and 4. If the test results differ, replace the relay.