- By simply checking the voltage in the ignition system, it is checked whether there is an ignition spark at all.
- Accurate visual inspection of the ignition system allows you to find the most common causes of defects (wires, connectors, voltage jumps, etc.).
- Only after that proceed to check the ignition system components.
Is there ignition voltage?
From the very beginning, we will check whether a spark is formed at all in the ignition system:
Disconnect the spark plug connector, unscrew the spark plug.
Reattach the plug to the spark plug and place it on the engine block so that it has good ground contact so that engine movements cannot reset it. It is even better to connect the threaded part of the candle with the help of an auxiliary starting cable to the engine.
Have your assistant turn the engine over with the starter.
If powerful sparks jump on the electrodes of the candle, then there is an ignition current and, most likely, the ignition system is in order.
However, there may be defects that are not detected in this way: a faulty sensor or incorrect calculation of the ignition timing by the control unit.
If there is no spark, take a spark plug from another cylinder. If there is still no spark, then you need to check the entire ignition system as a whole.
Stopping the ignition: with the ignition off, disconnect the connector «1» on the rear of the DIS ignition module «2».
Is there ignition voltage? Place the spark plug with the connector on the engine so that it has good ground contact. Have your assistant turn the engine over with the starter. If powerful sparks jump on the electrode of the candle, then there is an ignition current.
Visual inspection of the ignition system
Are all wire connectors and plug contacts securely connected to the DIS ignition module and to the ignition/injection control unit?
Maybe a single pin in the multi-pin connector on the control unit has disconnected?
Is the sealing compound squeezed out on the DIS ignition module? Then the module is probably defective.
Are there cracks or burn marks on the housing of the DIS ignition module?
Additionally, check the main ignition wire for tight connections and damage to the insulation. Modern ignition systems are especially sensitive to spark breakdown and leakage currents due to high voltages.
Are all parts of the ignition system clean and dry? Wet dirt contributes to voltage breakdown.
Tip: For the following measurements, make sure that the measuring and control devices are connected and disconnected only with the ignition off.
Checking the voltage supply to the ignition system
Along with the complete failure of the ignition system due to lack of voltage, insufficient voltage can also lead to significant system malfunctions! Therefore, it is better to use a voltmeter here. Test condition: charged battery.
Disconnect the connector behind the DIS ignition module.
With 1.8L and 2.0L engines, connect a meter to the disconnected connector between pin «3» and engine weight.
On a Vectra with a 1.6L engine, to the disconnected wire connector, connect a measuring device between the contact «1» (plus) and contact «2» (weight).
Everyone: turn on the ignition.
Must read at least 11.5 V.
If the device does not show voltage at all or shows too low voltage, then the defect lies in the wire to the ignition switch.
Sources of faults
Faulty ignition switch (chapter «Tools and devices).
There is no continuity in the lead wire from the ignition switch to the DIS ignition module or to the control unit. Verify, using the wiring diagram in this book, the entire length of the wires and connectors.
Checking the ignition coil
First, it is checked whether the candles give a spark. If yes, then the DIS ignition module is probably OK.
If not, check the voltage supply as described. If there is voltage but no spark: check ignition pulses (moving away from the control unit) as described below.
There is voltage and ignition pulses, but no spark: then the DIS ignition module is faulty.
A visual inspection of the DIS ignition module has already been carried out.
Ignition pulse test: Disconnect the connector on the rear DIS ignition module.
Connect to contacts «1» And «3» disconnected connector LED voltage indicator.
Have your assistant operate the starter: the voltage indicator should flash.
Carry out the same check in vehicles with a 1.6L engine between the contacts «1» And «4» and vehicles with 1.8 and 2.0 liter engines between the contacts «2» And «3». During this test, the voltage indicator should also flash.
If the LED flickers, then the ignition pulses are sent to the module. If the ignition is not working, only the DIS ignition module may still be defective.
If the impulses are not received, then the reason is in the control unit, in the supply wire or in the voltage supply to the control unit.
Checking the encoder
The sensor is located in the direction of travel on the left in the engine compartment behind the crankshaft belt pulley. The connection of the plugs of its wires is carried out on the right side up, so the voltage measurement does not need to be carried out under the car.
Follow the routing of the sender wire to the wiring harness, check the plug connections and wires.
Disconnect the impulse sensor connector in the engine compartment.
Connect the meter to the sensor wire.
Operate the starter: the meter between terminal 1 and terminal 2 should indicate more than 1V.
If the voltage is OK, unscrew the pulse generator from the engine block.
Clean the end face of the encoder. Dirt or grease in this area interferes with its function.
Check the air gap between the sensor/ring gear with a template.
The distance should be 0.1-1.5 mm.
The workshop has an additional opportunity to observe the voltage curve of the sensor on the monitor.
Do I need to check the control unit myself?
The ignition/injection control unit is on the left: in the relay box in the engine compartment. On checking the control unit, the art of an amateur ends. The risk of harm due to a mistake when connecting to the connector is too great. A new control unit is not cheap.
In addition, the likelihood that the cause lies in the control unit in the event of an ignition failure is assessed as insignificant.
Most often, the source of the malfunction lies in other components of the ignition system. Damaged wires or loose connectors are found by visual inspection. There is still a check of the ignition coil or high-voltage assembly, as well as a Hall sensor or an inductive impulse sensor. If after the described checks nothing is found, then it is best to send the car to an Opel or Bosch workshop. Faults in the ignition system will be found much faster with a suitable device in the workshop than an amateur can do.
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