Note: The electric fuel pump and its electrical circuit are part of the EEC - IV system, so the most complete diagnosis can only tell how well the pump and electrical circuit are working. A pump failure results in a loss of fuel flow and/or pressure, usually noted as a decrease in performance. If there is any suspicion, it is better to do a primitive pump check. A more detailed examination of the electrical circuit should be done by a specialist.
Warning: Gasoline is extremely flammable, so precautions should be taken when working on any part of the fuel system. Do not smoke, allow open flames or bare lights in the work area.
1. Before starting work, always check that the fuel tank is full of fuel and that there are no leaks in the pipes and their connections.
2. The easiest way to determine if the fuel pump in the gas tank is working is to turn the ignition key to the on position again, then when the pump is working you will hear a buzzing sound of an electrical signal.
3. Locate the inertia switch and, using a test lamp with an independent power source or a tester, make sure that the pump is energized (see figure). If the switch has opened the circuit, reset it.
4. Lower the gas tank (see section 5), using a test lamp with an independent power source or a tester, check the integrity of the positive contact of the pump and its ground terminal (see figure).
4.4. After turning off the ignition, check the integrity of the electrical circuit between the positive and negative contacts of the pump - if there are no breaks in the circuit, check the operation of the pump itself by connecting the wire to its "positive" terminal.
1. Sensor contact "ground".
2. Positive contact of the sensor.
3. Positive contact of the pump.
4. Pump ground contact.
5. From the flange.
6. Release.
7. Return.
5. No voltage means the pump is broken. Replace it (see section 7).
6. If there is voltage, connect the battery to the positive terminal of the pump. It will start working.
7. If the pump works, there may be a break in the circuit between the battery and the pump. Check and repair (use the electrical diagrams at the end of this book).
8. If the pump does not work, replace it (see section 7).
9. A more serious check of the electric pump, its relays and circuits should be carried out by specialists.
(The original article is available on the website FORDBOOK)