92Rocky-EC-Emission_Control_System-Part1
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DAIHATSU
Ro 1: ky
EMISSION CONTROL SYSTEM
INTRODUCTION EC- 2 PURPOSE OF SYSTEMS EC- 2 COMPONENT LAYOUT & SCHEMATIC
DIAGPAM EC- 3 Posmvlz cRANKcAsE vENT|LAT|oN
(Pcv) sYsTEM Ec- 4 FUEL EvAPoRAT|vE EM|ss|oN coNTRoL
(EVAP) svsTE|v| Ec- 5 THROTTLE Posmouen (TP)
EXHAUST GAS RECIRCULATION
(EGR) SYSTEM EC-10 THREE-WAY CATALYST (TWC)
SYSTEM EC-13
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EMISSION CONTROL SYSTEM
INTRODUCTION
PURPOSE OF SYSTEMS
System Abbreviation
Purpose
Positive crankcase ventilation PCV
EVAP
Throttie positioner TP
Fuel evaporative emission control
Exhaust gas recirculation
Three-way catalyst
(Catalyst under fioor.) TWC
Electronic fuel injection* EFI
Reduction of lolow-by gas (HC emission)
Reduction of evaporative HC emission
Reduction of HC and CO emissions
Reduction of NOx emission
Reduction of HC, CO and NOx emissions
Regulation of all engine conditions for reduction of
exhaust emissions
* For inspection and repairs ofthe EFI system, refer to the EFI section.
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EMISSION CONTROL SYSTEM
COMPONENT LAYOUT & SCHEMATIC DIAGRAM
Throttie
Intake air temperature
sensor
Throttie position sensor
Fuel pressure Air chamber regulator
A
IW
Gas
v Pressure ,
sensor
vemme IPVS Speed Sensor
Dwstributor
f Throttle
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EMISSION CONTROL SYSTEM
POSITIVE CRANKCASE VENTILATION SYSTEM (PCV)
To combat air-pollution problems, the engine is equipped with a sealed type positive orankoase ventilation system in order to prevent blovv-by gases generated inside the crankcase from being released into the atmosphere. The blow-by gases generated inside the crankcase flow into the cylinder side through the gas path of the cylinder block. When the opening degree of the throttle valve is small, oil in the blow-by gases is separated by the oil separator provided at the cylinder head cover. Then, the blow-by gases are sucked into the cylinders from the throttle loody to be burnt again. Fresh air enters the cylinder head cover from the upstream path of the throttle valve. At this time, the air flow rate is regulated by a jet provided at the cylinder head cover, thus stabilizing the engine idling. When the opening degree of the throttle valve is large and/or when a large amount of blovv-by gases are generated, the blovv-by gases are sucked into the combustion chambers both through the upstream path and the
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EMISSION CONTROL SYSTEM
FUEL EVAPORATIVE EMISSION CONTROL (EVAP) SYSTEM
The fuel evaporative emission control system employs the charcoal canister type. Pressure created by evaporating fuel drives the vapors into the charcoal canister which uses activated carbon to absorb HC emission. The separated HC emission is drawn into the throttle body to be burnt together with mixture in the combustion chamber when the BVSV opens according to the engine coolant temperature.
Thronle body
Lili
Purge port
Purging line
Fuel tank
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EMISSION CQNTROL SYSTEIVI
Coolant temp. or BVSV Throttle valve
tank pressure opening position (1) (2)
* CheCk Va"/fi Fuel filler cap
check valve
Evaporated fuel (HC)
HC from fuel tank is absorbed by
Positioned below
_ canister
Positioned above
HC from canister is sucked into engine
High pressure in fuel tank
- - _ OPEN CLOSED CLOSED
HC from fuel tank is absorbed by canister
High vacuum in fuel tank
CLOSED OPEN when Air is led into _ ""
CLOSED OPEN [excessive highJ fuel tank J
*:(1)...Charcoa| canister, (2),..Safety valve positive side, (3)...Safety valve negative side
INSPECTION OF FUEL VAPOR LINES, FUEL TANK, FILLER CAP & SAFETY VALVE
1. Visual inspection of fuel vapor lines and connections
Check the lines and connections for loose connections, kinks or damage.
2. Visual inspection of fuel tank
Check the fuel tank for deformation, cracks or fuel leakage.
3. Visual inspection of fuel filler cap
Check the cap and gasket for damage or deformation.
Repair or replace the gasket and/or cap, if necessary.
(1) Remove the quarter trim RH by detaching the eleven
(3) Disconnect the hoses from the safety valve.
Retum-pipe Safety
ki
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EMISSION CONTROL SYSTEM
(4) Ensure that there exists resistance when you blow your breath lightly from the siole A. Also, ensure that the resistance no longer exists when you blow your breath strongly. (5) Ensure that there exists resistance when you suck air lightly from the side B. Also, ensure that the resistance no ionger exists when you suck air strongiy.
INSPECTION OF CHARCOAL CANISTER
1. Disconnect the rubber hoses and remove the charcoal
canister.
2. Visual inspection of charcoal canister case
Visually inspect the charcoal canister case for cracks or damage.
3. Check of filter for restriction
(1) Blow low pressure compressed air into the tank pipe. Ensure that air Hows without resistance from the other pipe. (2) Blow air into the purge pipe. Ensure that no air Hows
from the other pipe. Replace the charcoai canister, if it exhibits any defect.
4. Cieaning of filter in canister
Clean the filter by blowing compressed air of Skg/cmz (43 psi) into the tank pipe while holding the other upper canister pipe closed. NOTE: ~ Do not attempt to wash the canister. ~ No activated carbon should come out during the test.
5. Install the charcoal canister and reconnect the rubber hose.
Purge Dipe
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EMISSION CONTROL SYSTEM
INSPECTION OF BVSV
TO.
Checking of BVSV by blowing air into pipe 1. Drain the cooiant from the radiator into a suitable container.
Remove the BVSV. Cool the BVSV to below 45°C (113°F) Ensure that no air continuity exists. If air continuity exists repiace the BVSV.
Heat the BVSV to above 66°C (151°F), using hot Water. Ensure that air continuity exists. If no air continuity exists, replace the BVSV. Apply liquid sealer to the threaded portion of the BVSV Reinstall the BVSV.
Tightening Torque: 2.5 - 3.5 kg-m
(18.1 - 25.3 ft-lb, 24.5 - 34.3 N-m)
Fill the coolant to the radiator. (See page CO-4.) Start the engine. Check the coolant level. lf the coolant level ls low, aolcl the coolant. Check the water leakage anol/or air leakage.
at
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THRQTTLE Pos|T|oNER (TP) sYsTEM
This system prevents the throttle valve from suddenly closing, thus reducing the CO and HC emissions
EMISSION CONTROL SYSTEM
conditions | TP diaphragm I Tnrome vawe
idling Pushed in by return force of throttle vaive | ldle speed position
Normai driving 1 Pushed out by diaphragm spring | Opened position
Deceleration I * Pushed in by return force of throttle valve | and then Sfowiy doses to me idle
At this point, the function ofthe air valve provided inside the throttle positioner diaphragm prevents the throttle valve from being
INSPECTION OF THROTTLE POSITIONER (TP) SYSTEM
Warm up the engine. Check the idle speed. Adjust the speed, if necessary. Check of TP setting speed (1) Raise the engine speed to approximately 3000 rpm. (2) Close the throttle valve slowly. (3) Observe the engine speed at a time when the dashpot
lever comes in Contact with the throttle lever. Engine Speed: 1600 i 100 rpm
If the engine speed does not conform to the specifica- tion, perform adjustment by turning the TP adjusting screw.
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EMISSION CONTROL SYSTEM
EXHAUST GAS REc|RcuLAT|oN (EGR) sYsTE|v|
The EGR system recirculates the exhaust gas into the intake manifold in an optimum amount according to driving conditions and coolant temperature. Thus, this system retards the combustion, resuiting in reduced amount of NOX emission.
Cooiant
temperature opening angle
EVSV Throw? EGR vacuum modulator
EGR valve
Exhaust gas
Closed Not recirculated
atmosphere
C¥osecl Not recirculated
Opens passage to
Open " Positioned between EGR
Closed Not recirouiated
(104°F)
pon Closed passage to
atmosphere
Open Recirculated
Closed passage to atmosphere
** Positioned above EGR
port
Open increase
Recirculate volume
REMARKS:
* At this stage, the EGR vaive repeats its opening/closing as described below, depending upon the throttle valve opening and
exhaust gas pressure.
Exhaust gas prfgssure drops. -a Modulatoropens. -> EGR valve closfs.
EGR valve opens. Modutator closes. e- Exhaust gas pressure increases.
** At this stage, the EGR valve remains open because of a negative pressure being applied tothe EGR port, even when the modulator
opens to the atmosphere.
EC-10
