Fuel System Testing - UNI-T UT106 Operating Manual

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
is installed right in the position and the dwell of the meter
can also indirectly used for the testing.
[1]
Start the engine of the automobile to achieve a rotation
speed of 3000 RPM.
So far as a GM automobile is concerned, set the
rotary switch to the DWELL and select 6CYL.
[2]
When the automobile is operating in a short fuel state
or in a long fuel state, the dwell of the meter should
be displayed between 10
(2) Fuel Injector Resistance Testing (see figure 18)
Model UT106: OPERATING MANUAL
0 0
and 50 .
Fuel Injector
Black
(figure 18)
42
Red