Malfunctions of the electronic fuel injection system, as a rule, do not cause engine failure. The malfunction is usually caused by a loose connection in the connectors and wire connectors, as well as fuel contamination, which leads to clogged injectors. Constantly check the reliability of the connections by lightly tapping on the connectors or twitching them - the signal should not disappear. Make sure that there are no mechanical damages on all contacts of the connectors and that both mating parts of the connector are inserted into each other up to the stop and fixed with latches. Before you start troubleshooting in the electronic injection system, be sure to check the condition of the ignition system. Make sure that the battery, fuses, fuses, connections to «weight», ignition coil, ignition coil high voltage wire, ignition distributor, spark plug high voltage wires and the spark plugs themselves are in good condition and operate without failure. Check ignition timing and engine idling speed. Check engine condition indicators such as cylinder compression and valve clearance.
Check for leaks in the power system. Make sure the fuel pump is working and check the fuel filter for dirt. Check the tightness of the parts of the air supply system. Disconnection or damage to items such as the engine oil level gauge, oil filler cap, or PCR hose may cause engine misfiring. Check the passage of air 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 commercially available equipment.