All four injectors open simultaneously, once per crankshaft revolution, providing two injections of fuel per cycle.
Checking, removing and installing
Start the engine and warm it up to normal operating temperature, then let it idle.
For a quick check, place the blade of a long screwdriver against the body of each injector in turn and listen for clicking sounds coming from the needle valves. A faulty injector will not click, in which case further testing is necessary.
Leave the engine idling and disconnect the connectors from each injector one by one. Engine speed should decrease by 100–2200 min⁻¹ when disconnecting the connector from each injector.
Stop the engine and disconnect the connectors from the injectors. Using an ohmmeter, check that the resistance between the two terminals of each injector is 12–16 ohms. If not, the injector is faulty and must be replaced.
To remove the injector, disconnect the wire from the negative terminal of the battery.
If the engine is hot, wait until it cools down.
Disconnect the fuel hoses from the fuel filter and pressure regulator. To prevent fuel splashing, wrap the hoses with a cloth before disconnecting them.
Disconnect the connectors from all injectors.
Remove the bolts securing the pressure regulator to the end of the fuel distribution line.
Remove the bolts and the fuel rail from the injectors.
Remove rubber sealing rings and bushings, injectors and insulators.
Figure 14.19. Injectors attached to the fuel rail for testing
To further test the injectors, install them on the fuel rail and secure them with wires (figure 14.19).
Temporarily connect the fuel distribution line between the fuel filter and the fuel return line.
Connect the cable to the negative terminal of the battery and turn on the ignition.
Connect the terminals of the fuel pump test connector together with a piece of wire and make sure that gasoline does not leak from the ends of the injectors (see figure 14.16). The appearance of a small amount of gasoline after 5 minutes is acceptable.
To check the volume of fuel injected by an injector, you need a measuring vessel, wires and a 12V power source.
Working with each nozzle in turn, place the end of the plastic tubing over the end of the nozzle and place the other end in the measuring vessel.
Connect the terminals of the fuel pump test connector and turn on the ignition.
Apply 12 V to the injector for 15 seconds and make sure that the injected fuel volume is 44–62 cm³.
Figure 14.20. Location of injector seals: 1 – sealing ring; 2 – fuel distribution line; 3 – sealing sleeve; 4 – intake manifold; 5 – insulator
Remove the control and measuring equipment and install the injectors in place. Installation is carried out in the reverse order of removal, while installing new rubber sealing rings (figure 14.20). Dip them in gasoline just before installing them and the fuel rail.