Test Point 16 - Injector Valves / Control System

TEST POINT 16: Injector valves Control system (V/Ohms)

If the engine can be run, pull off the injector valve plugs one after the other. If the injector valve is in good working order and combustion in that cylinder is correct, engine speed will fall. If the engine cannot be run, check:

a) Power supply
- Pull off injection valve plug (to do this, first remove the cover over the ring pipe). Remove LH relay XXV and bridge terminals 87 and 30 at the relay base. Connect voltmeter to the valve plug contacts and ground, using the test leads. Display: battery voltage If no battery voltage is displayed, check the current flow path according to the wiring diagram.

b) Check injection valve coil resistances
- Pull off the valve plugs. Use an ohmmeter at the injection valve connection contacts to measure the coil resistance.

Test value: approx. 16 Ohms

c) Injection output stage
- Adjust the oscilloscope in accordance with the manufacturer's instructions. Connect a Bosch test lead (1 684 463 093) between one injection valve and plug. Connect the tester lead to the test lead in accordance with the manufacturer's instructions.

CAUTION: Tester leads must not have any contact with ground.




- Start the engine. If the injection output stage is working correctly and the tester connections are correct, these displays must appear:

Condition: Starter speed

NOTE: If the engine does not start or if idle speed drops, interchange the tester connections at the test lead and check the tester selling.