Dacia Pick-Up 1304/1305/1307. Manual - part 36

IGNITION AND  INJECTION

17

17 - 8

Fig. 3

The valve potentiometer consists of a first potentiometer, working on the range

 (0° - 22°) and a second one, working on the range (19° - 90°). A common area is noticed,
between (19° - 22°) established for a more precise reading of the load necessary in the
partial load area, the most used for the engine exploitation.

The connector of the valve potentiometer consists of the following connections (drawing 2):

1

 - Mass  ( pin 27 computer )

2

 - Potentiometer I ( 0 

0

 - 22 

0

 )

3

 - Blank

4

 - Potentiometer II ( 19 

0

 - 90 

0

 ).

5

 - Supply ( 15 V, pin 25 computer ).

In can be checked by means of means of an oscilloscope as follows:

- engine on contact;
- manual moving of the control clutch lever;
- oscilloscope contacted to the pins 1 and 2 of the connector; if the displayed sign

looks like a row of horizontal straight lines with no interactions the potentiometer is ready
to use (drawing 10)

In case of damage, the potentiometer is not to be repaired – the lower part of the injection

central unit is to be replaced.

The wires of the potentiometer connector should be checked by an ohmmeter. The

following values are indicated for a good potentiometer:

- potentiometer I

R

1-5

 = 600 – 1400 Ù

- potentiometer II

R

2-4

 = 400 – 4000 Ù;the maximal values should

contact each other within the partial load area.

Fig.4

DESCRIPTION OF THE SYSTEM

17

IGNITION AND  INJECTION

17 - 9

REGULATOR OF  IDLE RUNNING

This regulator (drawing 1, position 9) is used to position the valve in order to obtain

the idle rotation. It is mounted into a case together with a switch. The idle running is
realized at the moment of switch contact closing (position 4), being necessary to the
normal idle functioning or to the engine brake.

The computer sends an electric signal to the regulator through the pins 32 and 34. The

regulator will position the valve in order to obtain the idle rotation   (800 ± 50 rot/min).

Components:

1

 - Electric motor step by step

2

 - Endless screw

3

 - Endless screwed wheel

4 

- Switch

5

 - Protection buffer

The switch connector and the idle motion actuator consist of:

1, 2

 - Actuator supply

( pin 32, pin 34 computer ).

3

 - Idle motion switch

( pin 8 computer ).

4

 - Mass

By connecting an ohmmeter to the

connector wires 3 and 4, one can see that
the switch positions:

- CLOSE  –  functioning status,

continuity

- OPEN – stand-by status, R =

Reference values measured at the

connected wires:

R

3-4 

= 0 – 200 Ù – contact close

R

3-4 

> 1 MÙ– contact open

R

1-2 

= 4 – 250 Ù

DESCRIPTION OF THE SYSTEM

IGNITION AND  INJECTION

17

17 - 10

IMPORTANT:

The connector disconnection and connection is to be done only with contact OFF for

the following checking and adjustment.

The basic adjustment of the valve (drawing 5) is the correlation between the potentiometer

position and the positioning engine of the valve. The adjustment is checked as follows:

- engine on contact;
- idle motion regulator supplied according to the diagram by a continuous source

having U = 5 – 6,5 V, necessary to lead it at the end of its way;

- the voltage U v and the partial voltage U 1 are measures on the potentiometer;
- the point with (U v, U 1) coordinates is marked on the diagram (drawing 6); in

case of a correct setting the point will appear on the shaded area of the diagram; if not

- the setting screw “3” should be rotated both ways.

Fig. 5

Fig. 7

Fig. 6

DESCRIPTION OF THE SYSTEM

17

IGNITION AND  INJECTION

17 - 11

EXAMPLE

:

When U v = 5 V, U 1 should be within 3.75 – 4.25 V for a correct adjustment.
This adjustment is used in case of changing regulator or of an irregular functioning

during the idle motion.

For checking the contact (drawing 7):

- engine on contact;
- regulator at the way, supplying an U = 5 – 6 V and helping it by hand;
- connection of the ohmmeter according to the drawing; we measure and R should

be zero;

- the partial voltage in this position should be U 1 = 0.19 – 0.22 V; in case this

condition is not fulfilled we can adjust it by the screw “B”.

NOTE:

The distance between the screw “3” and the axle “2” should be 1 mm at cold, in

order to avoid the idle rotation increasing when the engine is hot.

The rotation sensor is of inductive

type and consists of:

1

 - Permanent magnet

2

 - Insulator body

4

 - Ferite core

5

 - Coil

The drawing also indicates:

3 – gearbox clutch casing; 6 – flywheel
for rotation sensor.

The flywheel has 60  equidistant

teeth; there are 2  teeth missing. The
space of the remaining 58 teeth is used
to watch the rotation while the space of
the 2 missing teeth is used to watch the
reference position of the crankshaft,
corresponding to the cylinders 1 and 4
at PMS.

ROTATION SENSOR

DESCRIPTION OF THE SYSTEM