General diagnostics of the electronic fuel injection system (since 1986) (Mazda Capella GC)

Malfunctions of the electronic fuel injection system, as a rule, do not cause engine failure. The malfunction is usually caused by a faulty contact connection in the connectors and wire connections, as well as fuel contamination, which leads to clogging of the injectors. Constantly check the reliability of the connections by lightly tapping the connectors or twitching them - the signal should not be lost. Make sure that there is no mechanical damage on all connector contacts and that both mating parts of the connector are inserted into each other until they stop and are secured with latches. Before you begin troubleshooting the electronic fuel injection system, be sure to check the condition of the ignition system. Make sure that the battery, fusible inserts, fuses, ground connections, ignition coil, high-voltage wire of the ignition coil, ignition distributor, high-voltage wires of the spark plugs and the spark plugs themselves are in good condition and work without failures. Check the ignition timing and engine idle speed. Check engine condition indicators such as cylinder compression and valve clearance.

Check for leaks in the fuel system. Make sure the fuel pump is working properly and check the fuel filter for contamination. Check the air supply system components for leaks. Disconnection or damage to components such as the engine oil level indicator, oil filler cap, or positive crankcase ventilation hose may cause engine misfires. Check the air flow through the air filter.

A comprehensive diagnosis of the electronic injection system requires a special diagnostic tool, but some tests and checks can be performed using standard equipment available on the market.