Repair Manual

17
IGNITION AND INJECTION
17 - 7
A sign shaped as follows will be displayed
on the oscilloscope screen. It is to be used for
the calculation of the injection time = t
i
.
The injection time value increases when
the battery voltage is lower than 12 V.
Reference values for the injector:
- resistance measured between the wires 2
and 3, R
2-3
= 6.3 - 7.4 Ù
- a maximum of 1 fuel drop at the injector/
1 minute is visually checked and admitted
when supplying the fuel pump by shunting
the terminals 30 and 87 of the relay R
1
, with
lose contact.
VA LVE POTENTIOMETER
The valve potentiometer (drawing 4, position B) is fixed on the injection unit at the
end of the valve axle and consists of a potentiometer a double way. This is supplied with
+ 5 V from the pin 25 computer and sends to the later a voltage signal proportional with
its position. Then the computer will control the injector and the induction coil.
The potentiometer consists of:
1 - Mass
2 - Potentiometer I
3 - Potentiometer II
4 - Supply ( + )
5 - Brushes
6 - Insulator
DESCRIPTION OF THE SYSTEM
vnx.su