Tecnotest SL31205 Bedienungsanleitung Seite 60

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OSCILLOSCOPE KIT _______________________________________________________________________
If a trigger level is set on the highest peaks, only explosion sparks will be displayed.
In this case, if a higher synchronism level is set, at about 5KV, the signal is more stable
but exhaust sparks peaks will be absent.
Interpretation of the secondary wave forms
Compare cylinder by cylinder. Note differences between the ignition peaks and the
spark voltages.
Specifications on that can be found in the vehicle instruction manual.
A high peak Volt value on the secondary or a high spark voltage on the secondary can
be caused by:
•
strong resistance in different parts of ignition: spark plug wires, cap, rotor or spark
plugs);
•
a lean air/gasoline mixture;
•
high compression pressure.
A low peak Volt value on the secondary or a low spark voltage on the secondary can be
caused by:
•
reduced or obstructed distance between the spark plug electrodes,
•
secondary insulation dispersion;
•
too rich air/gasoline mixture;
•
poor compression.
The spark length should range between 1 to 3 milliseconds for all cylinders.
Fronts with an excessive voltage indicate too much turbulence inside the cylinder or a
wrong air/gasoline ratio.
56 OPERATING INSTRUCTIONS