Ignition, Secondary (Rod Continuous)
| Measurement: | Plot of all ignition voltages (continuous display) with the engine idling. |
|---|---|
| Check Objective: | Determining the differences between the ignition voltages for the individual cylinders. |
Preparation
Caution - high voltage! Observed safety advice! Engine oil temperature > 20 �C.
Connections
| INPUT A | COM/TRIGGER |
|---|---|
| Clamp the secondary measurement sensor across the ignition lead (4) from the ignition coil to the distributor. Connect ground connection to ground. | Clamp the trigger probe across the ignition lead from cyl. 1. The marking on the trigger probe must point towards the spark plugs! Connect the COM connection to the ground. |
Procedure
Start the engine and allow it to idle.
Reference Curve
To do this, deactivate the automatic mode using the [AUTO RANGE] key and select a smaller measurement range by pressing the [mV] key.
The evaluation is limited to the consideration of the voltage peaks for all cylinders. These should all be approximately the same height. Deviations of up to 4 kV are permissible. If the voltage spike of one cylinder continues to display excessive deviation after an extended examination period, do the following:
Fault Scheme 1
Symptoms:
The ignition voltage for an single cylinder is too high or too low (too high in this instance).
| Possible Causes | Countermeasures |
|---|---|
| Faulty spark plug | Check spark plugs have correct and uniform electrode gap and heat range. |
| If this is so, or if the ignition voltages continue to deviate excessively from one another following reinstallation of the spark plugs, the corresponding spark plug must be exchanged with a spark plug from another cylinder. This spark plug is faulty if the fault is now transferred to the other cylinder. | |
| Faulty carburation, open-circuit in the secondary circuit, fault in the engine machinery. | If the fault is not transferred, further tests are necessary (ROD single). |