Dacia Solenza 2004, Repair Manual

Page: 85 / 891

ENGINE E7J - 262
14
14 - 2
ANTI-POLLUTION
Petrol vapors re-aspiration
OPERATING PRINCIPLE
The communication of the tank with the
atmosphere is done through the carbon can.
The petrol vapors are retained when they are
passing through the active carbon from the carbon
can.
By means of a purging valve controlled by a
RCO signal issued by UCE injection, the petrol
vapors are re-aspired through piping by the intake
manifold.
The flow section of the purging valve is
variable, subject to the balance given by the
magnetic field created by supplying the purging
valve coil and the power of the spring ensuring
the valve closing.
RE-ASPIRATION CONDITIONS
The can-purging valve is controlled by
pin
4
of the UCE injection, in the moment when:
- water temperature >
20 ° C
;
- air temperature >
10 ° C
;
- engine is running over a certain im-
posed charge;
- valve potentiometer is not in the posi-
tion acceleration pedal not pressed .
By using the CLIP tester, it is possible the
reading of the RCO value (opening cyclic
ratio).
The purging valve is closed for a value
smaller than 0.7%.
OPERATION CHECKING OF THE
CAN PURGING VALVE
A defective operation of the petrol vapors
re-aspiration system, may lead to an unstable
idling or even to the engine stopping.
First of all, check:
- circuit conformity (see the operating
diagram)
- piping condition between the can and
the fuel tank (sealing, circuit clogging).
The ( B ) piping coming from the tank shall
be clogged.
Connect a manometer
(-3…+3 bar
) at the
( M) connection for communication with the
atmosphere and check at idling if there is
depression.
Is there depression?
YES – Set contact off. Using a
vacuum pump, apply a
500 - mbar
depression
at the (
A
) piping connection of the purging
valve. The value of the red depression must
not have a variation more than
10 mbar
within 10 seconds.
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