2. Check the state of charge of the battery. The normal operation of sensors and actuators for fuel dosage depends on the supply voltage.
3. Check the condition of the air filter - a dirty filter element can cause a significant deterioration in performance, including efficiency.
4. If a blown fuse is found, replace it and check the operation of the related circuit. If the fuse blows again, find and repair the problem.
5. Check the tightness of the air duct from the filter to the intake manifold. The presence of air leakage in the duct leads to excessive depletion of the mixture. Also check the condition of the vacuum hoses connected to the intake manifold.
6. Remove the air duct from the throttle chamber and check for carbon deposits and tar deposits. If dirty, wash the body with an aerosol carburetor cleaner and clean with a toothbrush (first make sure the cleaner is harmless to oxygen sensors and converter).
7. With the engine running, hold a stethoscope to each of the injectors and listen for the characteristic clicks that indicate the normal operation of the injectors. If you don't have a stethoscope, use a long screwdriver. Attach the tip of the screwdriver to the nozzle, and bring your ear close to the handle.
8. If listening gives questionable results, then check the nozzles with a light indicator by plugging it into the nozzle connector. Start the engine and check that a light flashes on each injector connector.
9. With the engine off, disconnect the connectors from the injectors and check the resistance of each injector. The resistance of each nozzle should be in the range of 13.4-14.2 ohms. If the resistance is different, replace the injector.
10. The rest of the checks should be carried out in a car service, as the reason for the abnormal operation of the system may be a malfunction of the control unit.