Tài liệu xe ô tô hyundai excel toàn tập hyundai excel
EMISSION CONTROL SYSTEM Return To Main Table of Contents GENERAL CRANKCASE EMISSION CONTROL SYSTEM 11 EVAPORATIVE EMISSION CONTROL SYSTEM 13 EXHAUST EMISSION CONTROL SYSTEM 20 GENERAL GENERAL The emission control system has the following three major systems Crankcase emission control system The crankcase emission control system is a system adopting a closed-type crankcase ventilation to prevent blow-by gases from escaping into the atmosphere The blow-by gases in the crankcase are routed back to the intake manifold for combustion Evaporative emission control system The evaporative emission control system prevents the emission of fuel vapour from the fuel tank, carburetor into the atmosphere It consists of various components (a canister, purge control valve, 2-way valve and so on) which collect and lead fuel vapour to the combustion chamber for combustion Exhaust emission control system The exhaust emission control system consists of an air-fuel ratio control unit (FBC system), three way catalytic converter, exhaust gas recircualtion (EGR) system, secondary air supply system to reduce emission of CO, HC and NOx EMISSION CONTROL COMPONENTS Components Crankcase Emission Control System Positive crankcase ventilation (PCV) valve Evaporative Emission Control System Canister 2-way valve (Overfill limiter) Purge control valve (PCV) Bowl vent valve (BVV) Fuel filler cap Fuel check valve Exhaust Emission Control System Jet air system FBC system (Air-fuel ratio control system) Catalytic converter Secondary air supply system Reed valve Secondary air control solenoid valve Exhaust gas recirculation system EGR valve Vacuum regulator valve (VRV) Thermo valve High altitude compensation system High altitude compensator (HAC) Heated air intake system Mixture control valve (MCV) FBC : Feedback Carburetor 29-2 Function Remarks HC emission control Variable flow rate type HC emission control Single diaphragm type Vacuum type With relief valve CO emission control CO, HC, NOx emission control CO, HC, NOx emission control CO, HC emission control Jet swirl type Oxygen sensor feedback type Three-way type With air control valve On-off solenoid valve NOx emission control Single type With vacuum control Wax pellet type CO, HC emission control CO, HC emission control CO, HC emission control Bellows type Vacuum control type Differential pressure type valve GENERAL TROUBLESHOOTING Remedy Probable cause Symptom Mixture control valve kept open Replace Vacuum hose disconnected or damaged Repair or replace EGR valve kept open Repair or replace EGR valve kept open Repair or replace High altitude compensation system faulty Troubleshoot the system and check components under suspicion Vacuum hose disconnected or damaged Repair or replace Faulty purge control system Troubleshoot the system and check components under suspicion Faulty bowl vent valve Replace Mixture control valve kept open Replace Faulty PCV valve Replace Exhaust gas recirculation system faulty Troubleshoot the system and check each component under suspicion High altitude compensation system faulty Troubleshoot the system and check components under suspicion Thermo valve faulty-cold engine Replace Intake air temperature control system faulty Troubleshoot the system and check components under suspicion Excessive oil consumption Positive crankcase ventilation line clogged Check positive crankcase ventilation system Poor fuel mileage Intake air temperature control system faulty Troubleshoot the system and check components under suspicion Exhaust gas recirculation system faulty Troubleshoot the system and check components under suspicion High altitude compensation system faulty Troubleshoot the system and check components under suspicion Engine will not start or is hard to start (Cranking possible) Rough idle or engine stalls Engine hesitates or poor acceleration 29-3 GENERAL EMISSION COMPONENTS LOCATION 29-4 GENERAL EMISSION CONTROL SYSTEMS A PCV valve B Canister C Bowl vent valve (BVV) D Reed valve E Secondary air control solenoid valve F EGR valve G Vacuum regulator valve (VRV) H Thermo valve GENERAL I High altitude compensator (HAC) J Vacuum switch K Air control valve M Overfill limiter 29-6 N Catalytic converter GENERAL VACUUM HOSE INSTALLING (FOR FEDERAL VEHICLES) GENERAL SCHEMATIC DRAWING (FOR FEDERAL VEHICLES) 29-8 GENERAL VACUUM HOSE INSTALLING (FOR CALIFORNIA VEHICLES) 29-9 GENERAL SCHEMATIC DRAWING (FOR CALIFORNIA VEHICLES) 29-10 ... HC from fuel tank is High pressure - in fuel tank - - Closed absorbed in the canister High vacuum in fuel tank - - - - Open Air is vented into the fuel tank 2 9-1 3 EVAPORATIVE EMISSION CONTROL SYSTEM... high-speed driving, there is less intake manifold vacuum available, and the blow-by gases are back up into the air cleaner through the breather hose Flow Characteristics Vacuum (mmHg) -5 00 -4 00 -3 00... Thermo Engine valve rpm Open Below 1450 High speed driving - Above Closed Check valve control in fuel filler valve cap Closed - Closed - Open - Evaporated fuel (HC) HC from fuel tank is absorbed into