Dacia Solenza (engine E7J). Manual - part 26

IGNITION AND  INJECTION

17

17 - 10

MULTI-POINT INJECTION CHARACTERISTICS

〈 SIRIUS 32 with 90 pins computer is managing the ignition and the injection.

〈 For diagnostic, CLIP Sagem tester is to be used.

〈 The injection system in use is a sequential multi-point type, injection and ignition phases

controlling being based on the SIRIUS 32 computer program logic, starting from the signal received
from the RPM sensor.

〈 The presence of the anti-pollution indicator OBD on the instrument panel, that is lighted for

3 seconds when setting the contact on, is specific to the vehicles observing pollution norms EURO
2000. The injection computer of these vehicles is provided with diagnostic system type OBD (“On
Board Diagnostic).

〈 Idling regime correction is subject to:

- climate maintenance on/off control (air conditioning)
- electrical balance on vehicle, as a result of connecting different electric consumers.

〈 EURO 2000 specific vehicles are provided with two oxygen sensors located in front of the

catalyst (upstream oxygen sensor) and after catalyst (downstream oxygen sensor).

〈 At EURO 2000 specific vehicles, the fuel supply is performed at constant pressure (3.5 ±

0.2 bar), the pressure controller placed in the fuel tank being provided for this purpose.

Characteristics

IGNITION AND  INJECTION

17

17 - 11

AIR CONDITIONING UNIT IS USING A COMPRESSOR

WITH VARIABLE DISPLACEMENT

The connections injection/air conditioning, are the followings:

- pin 46 of the injection computer is receiving the information “ air conditioning

request” further to the air conditioning switch acting;

- pin 10 of the injection computer will transmit the coupling control of the air

conditioning compressor by means of the “A” relay, if the coupling authorization conditions are
accomplished.

The information “power absorbed by compressor” displayed when performing diagnostic by

means of the CLIP tester, is related to the couple value taken by the compressor. This is of 300-
5000W, the minimal displayed value being of 300 W, regardless the compressor coupled / uncoupled
condition.

The injection computer is forbidding the compressor coupling in the following situations:

- at less than 16 seconds from engine starting;
- subject to the power requested to the engine by the vehicle driver.
- when  the acceleration pedal is fully pressed;
- if the engine RPM is lowering till 550 rot/min (compressor is again coupling if the RPM is

reaching to 1800 rot/min);

- if  the  water temperature has increased to over 110° C;
- if  the  engine RPM is exceeding 6000 rot/min.

Injection / air conditioning strategy

IGNITION AND  INJECTION

17

17 - 12

IDLING REGIME CORRECTION SUBJECT TO BATTERY VOLTAGE AND TO

ELECTRIC BALANCE ON VEHICLE.

This correction is dedicated to the compensation of the voltage drop due to the electric consumers

starting, when the battery is weaker charged. In this purpose, engine RPM is increased, allowing in
this way the alternator rotation increase and consequently of the battery voltage.

More the lower is the voltage, more important the applied correction is. So, a variable correction

is applied, starting when voltage is reaching 12,8 V. The correction is starting from the nominal
idling RPM and may increase with maximum 150 rot/min additional.

Idling regime correction

IGNITION AND  INJECTION

17

17 - 13

PRINCIPLE

In engine normal operation conditions at warm, the RCO value is varying between a high and

a low limit, in order to obtain the nominal idling regime. Further to an operation dispersion
(running in, engine clogging, etc), it may be possible that RCO idling value to be situated next to
the lower and higher values.

The adaptive correction of the “RCO idling” parameter is allowing obtaining of slow variations

of the engine air requirement, so that RCO value centering on an average nominal vale is obtained.
This correction is becoming effective unless the water temperature is over 80°C, at 20 seconds
after engine starting and if it is in the nominal idling adjustment phase.

“RCO IDLING” AND “ IDLING ENRICHING ADAPTATION” VALUES

PARA METER

RECOMMENDED VALUE

PR006: Engine regime

750 rot/min

PR022: RCO idling

5%< X < 12%

PR031: Idling enriching adaptation

80 < X < 176

At each engine stopping, the injection computer is controlling the performing of a new position-

ing of the step-by-step engine, bringing it to the bottom limit. This function so called “re-setting”, is
maintained for 8 seconds.

INTERPRETATION OF THE PREVIOUSLY MENTIONED  PARAMETERS

In the situation of an air excess (infiltration air, valve body inadequate attachment, etc), the idling

regime will increase and the “RCO idling” value will decrease in order to return to the nominal
idling regime. The value of the RCO idling adaptive correction will decrease in order to centering
again the idling adjustment operation.

In case of an air lack (clogging, etc) the reasoning is opposite: “RCO idling” is increasing, and

the value of the “RCO idling” adaptive correction will increase in order to center again the idling
operation on an average nominal value.

IMPORTANT: After erasing the failures memorized by the injection computer, it is necessary

to start the engine then stop it, in order to achieve in this way the re-setting of the step-by-step
engine. Start then again the engine and let it idle run until reaching the nominal idling regime, in
order to achieve a correct re-setting of the adaptive correction.

Idling regime adaptive correction