Note: The following procedure assumes that the fuel pump is working properly and the fuel pressure is correct (see section 3).
1. Check all wiring connectors related to this system. Loose connections and poor ground connections can cause serious malfunctions.
2. Make sure the battery is fully charged, as the control unit and sensors must be supplied with the required supply voltage to measure the amount of fuel correctly.
3. Check the air filter - a dirty or partially clogged filter will greatly reduce engine performance and fuel economy (see Chapter 1).
4. If you find a blown fuse, replace it and see if it blows again. If it does, look for a short to ground in the fuel pump wiring.
5. Check the air intake duct from the air flow sensor/air cleaner to the intake manifold for leaks that could cause a lean fuel mixture. Also check the condition of the vacuum hoses connected to the intake manifold.
6. Disconnect the air intake duct from the throttle body and check the throttle body for dirt, carbon or other deposits. If it is dirty, clean it with carburetor cleaner and a toothbrush.
(The material is based on data from the website: MitsubishiMan.ru)
7. On engines with multi-point injection (MPI), with the engine running, apply a screwdriver to each injector in turn; a clicking sound from the handle will indicate that the injector is working correctly.
8. On all models, the rest of the check must be performed by specialists, since incorrect actions may damage the control unit.