Checking functionality
1. Check the injection system fuses (FUEL INJ). Replace faulty fuses.
Models up to 9/89.
1. Connect the terminals of the fuel pump test connector with a cable. The cable remains connected during the test.
Models from 10/89.
1. Connect the F/P and GND terminals with a cable. The cable remains connected during testing.
2. Turn on the ignition, do not start the engine.
3. Remove the gas cap and check if the fuel pump makes noise. If there is no noise, check the wires according to the diagram for a break. If the wires are OK and there is still no noise, then check the fuel pump relay.
Checking the fuel pump relay
1. Remove the rear seat, see Chapter Body, car painting, car care.
2. Turn on the ignition.
3. Measure the voltage between the V/P terminal using a voltmeter (up to 9/89 year of issue with GR terminal) and mass. It should be 12 V.
4. Turn off the ignition.
5. If the voltage is not correct, unscrew the side trim of the center console in the passenger footwell. The fuel pump relay is located next to the control unit.
6. Turn on the ignition.
7. Check that the relay switches audibly. If the relay does not switch, the relay resistance should be checked.
8. Disconnect the connector on the relay.
9. Measure the resistance between the terminals using an ohmmeter.
| Terminals | Resistance in Ohm | |
| up to 9/89. | since 10/89 issue. | |
| STA-E1 | 15 — 30 | 21 — 43 |
| B — Fc | 80 — 150 | 109 — 206 |
| B — Fp | ||
10. If one or more values are not as specified, the relay should be replaced. If the relay is OK, the fuel pressure should be checked.
Checking fuel pressure
Verification conditions: The battery is fully charged (12 volts), the fuel filter is in perfect condition.
Based on website data: www.MAZbook.ru
1. Equalize the fuel pressure.
2. Disconnect the fuel line between the fuel filter and the distribution line on the filter, after loosening the clamp.
Caution: Place a rag around the fuel line as fuel may leak out.
3. Connect the pressure gauge with a fuel-resistant auxiliary hose to the fuel filter.
4. Turn on the ignition, do not start the engine.
5. Measure the fuel pressure. Required value: 4.4-5.8 Bar.
6. If the value is not as specified, the fuel hoses and connections should be checked for damage, leaks and blockages. If the hoses are in good condition, the fuel pump should be replaced.
7. Turn off the ignition.
8. Disconnect the cable from the diagnostic connector.
9. Remove the auxiliary hose and pressure gauge and connect the fuel hose, securing it with a clamp.
10. Start the engine and check the fuel system for leaks.