Checking the fuel discharge pressure

■ Connect a pressure gauge to the injector supply line 1895890000.

■ Pull out the control switch i to terminals 87b and 30 connect the connection cable to the socket (2).

■ Turn the ignition switch to the "Drive" position”.

■ Disconnect the pressure regulator pipe from the intake manifold.

■ The fuel delivery pressure must be up to 3.5 ± 0.2 bara (0.35 ±0.02 MPa), and the power consumption of the pump should not exceed 6…7 A.

■ If the pressure does not exceed 3 barium, close the pressure gauge valve. Now the pressure should be over 4 bars, otherwise, the pump will be damaged, which needs to be replaced.

■ If the fuel pressure does not reach the required value with the pressure gauge valve open, clamp the return cable. An increase in pressure indicates that the pressure regulating valve is damaged, which needs to be replaced.

■ If the fuel pressure exceeds the required value with the pressure gauge valve open, should be checked, that the supply and return lines are not kinked. Also check, that the fuel filter is not clogged.

■ Furthermore, with the engine running and the pressure regulator line connected to the intake manifold, check, whether the fuel pressure changes with changing the position of the gas pedal” in the following way:

– at idle, the pressure should be 2.5 ± 0.2 bar,

– with a quick depress of the pedal, the pressure should exceed 3.5 ± 0.2 bar.

 

Checking the auxiliary air valve for leaks

■ Let the warm engine idle.

■ Clamp the rubber hose to the valve with universal pliers. The engine speed should not be reduced by more than 50 rpm. Otherwise, the valve is leaking and must be replaced.

■ At the same time, check the connection of the supplementary air for leaks.