B27-40: Injectors, Fuel Distributor

Injectors, fuel distributor
Operations B27-40

B27



Remove the injectors from the cylinder head




Turbo: first disconnect the fuel lines from the injectors. Take care not to bend the pipes.

Then remove the injectors and connect them to the fuel lines.

B28



Make sure that the fuel distributor does not leak
Turn on the ignition to start the fuel pump.

Observe the injectors, they can become moist but must not start to drip.

Turn off the ignition.

Injectors drip: internal leakage in fuel distributor, replace the complete fuel distributor.

B29



Check the injectors at rest pressure
Lift up the air flow sensor plate to open the slits in the control pressure regulator. and observe the injectors.

The injector may become moist but mutt not drip during 15 seconds.

One or more injectors leak: clean the injectors and test with the test apparatus.

B30



Check the difference between the fuel delivered from each injector

This test should only be carried out in cases of obvious engine malfunction. Otherwise, continue with operation B40

There are two different types of measuring equipment in use:
- meter 0976 (USA + Canada only), tee operation B34.
- fuel metering unit 5014. see operation B31 below.


Fuel metering unit 5014
Operations B31-33

B31



Connect fuel metering unit 5014
In order to obtain comparable results, all of the hoses should either be empty or full at the start of the test.

B32



Check injector deviation
Turn on the ignition to start the fuel pump.

Lift up the sensor plate to half its travel. Keep it in this position until 100 cm3 of fuel has been delivered in one of the measuring cylinders. Then release the plate.

The injectors should start delivering fuel at the same time. The max. fuel deviation, i.e., the difference between the largest and smallest amounts of fuel delivered, must not exceed 20%.

Turn off the ignition.

Greater then 20 %: repeat the test to be exactly sure.




If the deviation 5 still greater then 20 %: swap the hoses between two injectors (one correct and one faulty) and repeat the test.

If the result is still the same: the injector or line is defective. Clean and test the injector using the test apparatus.

If the other injector malfunctions: the fuel distributor is defective and will have to be replaced.

B33



Disconnect the measuring equipment
Pour the fuel back into the tank

Continue with B40


Meter 0975
Operations B34-39

USA and Canada only.

Note: The fuel pump must be running during the test. A battery charger can be connected to prevent the battery from becoming discharged.
Low battery voltage will decrease the fuel pump capacity and the test results will be invalid.

B34



Connect meter 0976
Support the meter on a flat surface, next to the car, and make sure that it is horizontal by checking the built in spirit (bubble) level.

Connect the injectors to the hoses from the meter, injector no. 1 to hose no. 1, etc.

Insert the meter return line in the fuel tank.

B35



Evacuate the meter
Turn on the ignition.

Lift up the air flow sensor plate to its max. position. Insert tool 0977 so that the plate does not move.




Depress the meter switches one at a time and open the meter knob. Continue until both the tubes in the meter are evacuated and free from air bubbles.

Remove 0977 and release the air flow sensor plate.

B36



Check the fuel flow at idle position

Turn the meter knob to the left (white spot).

Depress the switch for injector no.1. Lift up the air flow sensor plate until a flow of approx. 6 cm3/min. is obtained. Keep the plate in this position with tool 0977.

Depress the switches for the remaining injectors one at a time in order to find out which injector has the lowest fuel flow.

Depress the switch for the injector with the lowest flow. Position tool 0977 so that the flow becomes 6.0, 6.6. or 7.2 cm3/min.

Check the fuel flow for the remaining injectors. The flow values for the remaining injectors can only lie above the set value.

Set value Max. permissible fuel flow
6.0 cm3/min. 72 cm3/min.
6.6 " 7.9 "
7.2 " 8.6 "

Incorrect fuel flow:
Turn off the ignition.




Swap a fuel line with an incorrect flow, with a feel line having a correct flow hat the fuel distributor).

Repeat the flow test.

If the fault still remains on the same injector. either the injector or the fuel line is defective. Clean the injector and test it in the test apparatus.

If the fault moves to the other injector. the fuel distributor is defective and will have to be replaced.

B37



Check the fuel flow at part load
Turn the meter knob to the right (white spot).

Position tool 0977 so that the fuel flow for the injector with the lowest flow becomes 40, 50 or 60 cm3/min.

Check the fuel flow for the remaining injectors.

Set fuel flow Max. permissible fuel flow
40 cm3/min. 46 cm3/min.
40 " 57 "
60 " 68 "

Incorrect fuel flow: turn off the ignition. Swap the fuel lines at the fuel distributor. Repeat the test, as previously described.

B38



Check the fuel flow at full load
Turn the meter knob to the right (white spot).

Lift up the sensor plate to its max. position. Check which injector has the lowest fuel flow. Position tool 0977 so that the flow for this injector becomes 120, 140 or 160 cm3/min. Select as high a value at possible.

Check the fuel flow for the remaining injectors.

Set fuel flow Max. permissible fuel flow
120 cm3/min. 131 cm3/min.
140 " 153 "
160 " 175 "

Incorrect fuel flow: turn off the ignition. Swap the fuel lines at the fuel distributor. Repeat the test, as previously described.

B39
Turn off the ignition and disconnect the test apparatus

B40



Reinstall the injectors

Turbo:
- refit the injectors.
- position the fuel lines. Take care not to bend the pipes.
- connect and clamp the feel lines. Make sure that they do not rub against any part of the engine.