Surtek MUL04 Manual De Usuario Y Garantía página 40

5. RPMx10 Testing (see Fig. 12)
Fig. 12
a. Set the rotary switch to RPMx10 and select the number of cylinders in the
automobile to be tested.
b. As prompted at the LCD connect terminal, insert thered test lead into the
terminal and the black one into the COM terminal.
c. Connect the black test lead probe to the ground (i.e. ground strap connection)
of the automobile and the red one to: the appropriate testing test terminal of
the computer of the automobile if the automobile is in a DIS type (Refer to the
servicing handbooks of various kinds of automotive manuals for the detailed
position); or the negative pole of the ignition coil if the automobile is equipped
with a distributor board (Refer to the servicing handbooks of various kinds of
automotive manuals for the detailed position).
d. The normal starting rotation speed of an engine is about 50 RPM to 275 RPM.
Refer the detailed position to the servicing handbooks of various kinds of
automotive manuals because this value relates to the current temperature,
engine size, battery size, etc.
WARNING
• The displayed value of the meter becomes the actual tach reading only after it
is multiplied by 10.
6. Fuel System Testing
It is necessary to add more accurate engine fuel control to a low injection
automobile. Since 1980, the automotive manufacturing industry has used
electronically-controlled carburetor and fuel injection so as to achieve lower fuel
injection.
1. GM (General Motor): Testing the dwell of the C-3 mixed-control solenoid:
Place the solenoid in a cylinder, monitoring the ratio between the air and the
fuel, which should generally be 14.7 to 1 between the air and the fuel so as to
reduce the injection of surplus fuel. The testing is used to see if the solenoid
40
Fig. 11