GENERAL INFORMATION 0B – 17
DAEWOO V–121 BL4
GENERAL DESCRIPTION
ON BOARD REFUELING VAPOR
RECOVERY SYSTEM
The NUBIRA 2.0 DOHC model is equipped with an On
Board Diagnostic Stage II (OBD–II) system to meet en-
hanced emission control requirements. Within this OBD–II
system, an On Board Refueling Vapor Recorvery (ORVR)
system has been developed and equipped to meet en-
hanced evaporative emission control requirements during
vehicle moving, parking, and refueling at gas stations. The
Daewoo ORVR system adopts one canister to collect both
evaporative vapors during the moving & parking as well as
refueling vapor. Collected vapor is consurmed by the en-
gine through the intake manfold during vehicle operation.
The mechanism of Daewoo ORVR system to meet the
ORVR requirement is to create suction inside filler neck by
the aid of fuel flow through a reduced diameter section in
the filler pipe.
Therefore, Daewoo ORVR system adopts the so called
”Liquid Trap” or ”Liquid Seal” system that assures the long
term durability.
The Daewoo ORVR system provides nozzle compatibility
with conventional and stage II vapor recovery nozzle.
The Daewoo ORVR system has been designed to have
the following functional features.
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To collect refueling vapors and to route to canister.
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To provide nozzle compatibility with conventional
and stage II vapor recovery nozzles.
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To provide fill shut off signal.
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To prevent canister from liquid fuel during normal
driving and vehicle rollover.
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To provide fuel tank venting to canister during ve-
hicle operation.
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To protect fuel tank from over–pressure.
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To protect fuel vapor dome from overfill.
Any failures or malfunction of the ORVR system will be
identified by OBD–II system and warned through Malfunc-
tion Indicator Lamp (MIL) on the instrument cluster.
No special refueling procedures and mainternance on
ORVR system are required.
The Daewoo ORVR system and all fuel system compo-
nents have been designed to prevent the electrostatic dis-
charge phenomenon by adopting mitigation techniques
recommended in SAE J1645. Daewoo’s own test proce-
dure (EDS–T–5005) is similar to SAE J1113.