Dacia SuperNova (engine E7J). Manual - part 25

E7J-A-2/60 ENGINE

IGNITION AND INJECTION

17 - 10

In case of an excess (false air, non-conforming attachment of the valve body, etc) the

idling regime will increase and the value “RCO idling” will lower, returning so, at the
nominal idling regime.

The value of the (PR 021) parameter will decrease in order to realign idling RCO (PR

022) within the optimal range. In case of a lack of air ( choking up, etc) the reasoning is
conversely : RCO idling (PR 022) will increase, and the value is adjusting RCO idling (PR
022) on a average nominal value.

IMPORTANT
After battery disconnection/reconnection, it is obligatory engine starting and maintain

it for several minutes in order to perform a correct resetting of the adaptive correction
of the RCO idling.

IDLING REGIME ADJUSTMENT

E7J-A-2/60 ENGINE

IGNITION AND INJECTION

17 - 11

The catalyst efficiency is maximal when the air excess value (l) is within the limits l =

0,97 ...1,03.

The injection computer is adopting the adjustment strategy of the fuel mixture enriching

in order to observe the a.m. condition. In order to inform the computer about the enriching
degree of the mixture, the oxygen sensor is used, which is sending an electric signal of a
value oscillating between 150 and 800 mV.

When the engine is warm and operating in the « closed loop « stage, the tension generated

by the oxygen sensor must quickly oscillate between 150 +/- 50 mV, corresponding to the
poor mixture and 750+/- 50 mV corresponding to the enriched mixture. The maximal-minimal
range must be as large as possible (at least 500 mV), confirming the sensor good operation.

The correction of the mixture enriching may be seen by means of the CLIP tester, in the

menu “FUNCTIONS TEST”, sub-menu “ENRICHING ADJUSTMENT” by the parameter
PR 035= enriching correction value.

The correction value has as limits 0 and 255, the average value being placed at 128.
The interpretation of the parameter PRO 35 value, is the following :

- when it is greater than 128 the computer is requesting the mixture enriching- so, the

mixture has been poor.

- when it is smaller than 128, the computer is requesting the mixture penury- so, the

mixture has been rich.

The entrance in the enriching adjustment is effective after a timing, due to water

temperature greater than 10 C when the acceleration throttle is free ( idling engine) and the
oxygen sensor is enough warm ( over 350 C). Until the moment of entering in this stage,
the enriching correction value (PRO 53) will be 128.

In the enriching stage, the injection computer will not take into account the values

furnished by the oxygen sensor, in the following situations :

- acceleration pushed at maximum
- sudden acceleration
- at decelerating, with free acceleration pedal information.
- in case of a damaged oxygen sensor.

“DEGENERATED” OPERATION WAY IN CASE OF THE OXYGEN SENSOR

DAMAGE

When the tension furnished by the oxygen sensor is not correct ( is changing a little bit

or not at all ), during enriching adjustment, the computer will not pass to the »degenerated »
operation way unless the damage has been recognized as being present for at least 10
minutes. Only in this case, the damage will be memorized.

When a damage at the oxygen sensor is detected and if the damage has been already memorized,

then it will pass directly to the « open loop » operation (enriching correction = 128).

ADJUSTMENT OF THE FUEL

MIXTURE ENRICHING

E7J-A-2/60 ENGINE

IGNITION AND INJECTION

17 - 12

ENRICHING ADAPTIVE CORRECTION

PRINCIPLE

In the “closed loop” stage, the enriching correction value (PR 035) is adjusting the

injection times in order to obtain a ratio as close as possible to the enriching value = 1.

The correction value is close to 128, having as limits 0 and 255; nevertheless, dispersions

of the injection system components may occur, that are giving the correction a displacement
towards 0 or 255, in order to obtain the enriching value 1.

The adaptive correction is allowing the injection chart displacement in order to re-

focus the enrichment adjustment (PR 035) on the 128 value.

The values of the adjustment correction may be read by means of the CLIP tester, as follows :

- connect the tester to the vehicle diagnosis socket and to the battery (or to the lighter socket).
- select

“

COMPUTERS TEST

”

, then

“

PETROL INJECTION

”

- in the menu

“

FUNCTIONS TEST

”

, access

“

ENRICHING ADJUSTMENT

”

, where

you can find parameters PR 030= enriching adapting in operation (the adaptive correction
for the partial and large charges area) and PR 031= enriching adapting at idling (adapting
correction at idling and in small charges area).

PARAMETER

FIELD

Enriching adapting in operation (PR 030)

80% £ X £ 176 %

Enriching adapting at idling (PR 031)

80% £ X £ 176 %

ENRICHING ADAPTIVE CORRECTION

E7J-A-2/60 ENGINE

IGNITION AND INJECTION

17 - 13

If values PR 030 and PR 031 are fixed on value 128 (after battery disconnecting/

reconnecting) then it is necessary to perform a specific road test, observing the following
conditions.

The adaptive corrections are active only when the engine is warm in the « closed loop »

stage (when PR 035 is variable) on an exactly range of the depression from the inlet manifold.
It is necessary that engine has been run in «closed loop » in more than one areas of the inlet
pressure, for which the adaptive corrections begin to progress in order to compensate the
enrichment from the engine operation.

ROAD TEST

This is performed in the following conditions :

- warm engine (water temperature greater than 75

- engine RPM not greater than 4800 rot/minute

driving on road, for a normal drive, on 5… 10 km distance.

For this test, it is recommended to start from an engine low regime, in III-d or IV-th

gear, with a gradually acceleration so that desired pressure gets stabilized in the inlet
manifold for 10 seconds in each area, as per the following table :

Average 255

Average 416

Average 546

Average 676 Average 807

Area 1

Area 2

Area 3

Area 4

Area 5

(mbar)

247----------- 351 --------------- 481 --------------- 611 --------------- 741 --------873

Further to this road test, the corrections must become valid.
Read again the values of the PR 030 and PR 031 parameters. These, initially being at

128, have been changed after this road test. If not, perform again this operation, strictly
observing the test performing conditions.

ENRICHING ADAPTIVE CORRECTION

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