Measurement; Starting Advance - tecnotest 138-E Manuel D'utilisation

__________________________________________________________________________ TIMING LIGHT
4.0 -

MEASUREMENT

4.1 -

Starting advance

ATTENTION:
The movable reference is usually located on one of the two extremities of the
engine shaft (hence on the wheel or on the pulley).
•
Start the vehicle to be tested.
•
After the connections to the engine have been carried out, press the
selection key (8) to select the 2 or 4-time cycle according to the type of tested
engine. On the basis of the selection the relevant led 4 times (2) or 2 times (4),
turns on.
•
In case the car to be tested is equipped with a vacuum device, disconnect the pipe
(if not differently indicated by the manufacturer).
•
Let the car idle and compare the value displayed by the timing light to that
supplied by the manufacturer making sure that they coincide.
•
Point the timing light towards the fixed reference and then hold down the
FLASH key (11); the flash starts flashing.
•
Rotate the DEVIATOR (10) until the display indicates the manufacturer's advance
value or until the movable reference corresponds to that fixed.
At the beginning (before acting on the DEVIATOR) the display shows the 10° values
(most common value in the engines).
•
Rotate the DEVIATOR to the left to increase the displayed angle, turn it to the
right to decrease it (see picture c).
•
The same operation performed with reference to the engine references will make
the movable reference move to the right or to the left.
•
Continuously press the DEVIATOR for a rapid increase or decrease, press the
DEVIATOR and release it immediately for a 0,1° increase or decrease.
•
The TDC fixed and movable reference marks on the engine have to coincide.
On the contrary, the advance is not correctly adjusted; correct the phase by
positioning the distributor.
•
Release the FLASH key (11) to stop the advance reading; the displayed data are
stored for some seconds.
NOTA BENE:
The advance adjustment described above can be carried out only on cars equipped with
distributor. As a matter of fact, in modern cars the role of this detail is played by the
electronic central unit. On this type of cars it is possible to check the advance angle
correctness only.
In case of one or more wrong advance values, check the ignition system.
OPERATING INSTRUCTIONS 35