EMISSION CONTROL SYSTEM 2.

EMISSION CONTROL SYSTEM 2. GENERAL CRANKCASE EMISSION CONTROL SySTEM... 9 EVAPORATIVE EMISSION CONTROL SySTEM 11 EXHAUST EMISSION CONTROL SySTEM 16

GENERAL GENERAL SPECIFICATIONS Y29CAOA Components Function Remarks Crankcase Emission Control System Positive crankcase ventilation (PCV) valve Evaporative Emission Control System Canister Purge control solenoid valve HC reduction HC reduction Variable flow rate type ON/OFF solenoid valve Exhaust Emission Control System Jet air system CO reduction Jet swirl type MPI system (air-fuel mixture control device) CO, HC, NOx reduction Oxygen sensor feedback type 3-way catalytic converter CO, HC, NOx reduction Monolith type Exhaust gas recirculation system NOx reduction EGR valve Single type Thermo valve Bimetal type SERVICE STANDARD V29CBOA Purge control solenoid valve Coil resistance Thermo valve temperature Opening temperature Closing temperature MIN. 50 C (122 F) 61-69 C (142-156 F) TIGHTENING TORQUE Nm kg.cm Ib.ft Y29CCOA Positive crankcase ventilation valve 7.8-12 80-120 5.8-8.7 EGR valve installation bolt 19-27 190-280 14-20 Thermo valve 20-39 200--400 14-29 SEALANT Y29CDOA Thermo valve thread portion Threebond 1104 or equivalent 29-2

GENERAL TROUBLESHOOTING Y29CEOA Symptom Probable cause Remedy Engine will not start or hard Vacuum hose disconnected or damaged Repair or replace to start The EGR valve is not closed Repair or replace Malfunction of the purge control solenoid valve Repair or replace Rough idle or engine stalls The EGR valve is not closed Repair or replace Vacuum hose disconnected or damaged Malfunction of the PCV valve Malfunction of the purge control system Repair or replace Replace Check the system; if there is a problem, check its component parts Engine hesitates or poor Malfunction of the exhaust gas recircula- Check the system; if there is a proacceleration tion system blem, check its component parts Excessive oil consumption Positive crankcase ventilation line Check positive crankcase ventilaclogged tion system Poor fuel mileage Malfunction of the exhaust gas recircula- Check the system; if there is a protion system blem, check its component parts 29-3

GENERAL EMISSION CONTROLS LOCATION 29y001 F 29'(002 A. PCV valve B. Purge control solenoid valve C. EGR valve D. EGR temperature sensor (California only) E. Thermo valve F. 2 way valve G. Catalytic converter H. Canister 29-4

GENERAL EMISSION CONTROL SYSTEMS A. PCV valve B. Purge control solenoid valve PCV valve \ Purge control solenoid valve 29YOO4 C. EGR valve D. EGR temperature sensor (California) E. Thermo valve 29YOO5 F 2-way valve EGA, temperature sensorr >--: (California only) --~ )1 ----- 29Y(K)6 2-waV valve 29YOO7 29YOO8 G. Catalytic converter H. Canister Catalytic converter 29V(X)9 29-5

GENERAL VACUUM HOSE LAYOUT [For Federal and Canada] Fuel pressure regulator FRONT U Thermo valve -ThfOttle body Purge control solenoid valve rl----(bi',--... Canister [For California] Fuel pressure regulator FRONT U EGR valve EGR control solenoid valve "'-+---f-~y)--.j G : Green Y : Yellow L : Light blue R Red B : Black Purge control solenoid valve R rt--~ib;--_ Throttle body Canister 29-6

GENERAL SCHEMATIC DRAWING (FOR FEDERAL AND CANADA).,. Oxygen sensor *2. Air-flow sensor *3. Intake air temperature sensor *4. Coolant temperature sensor *5. Throttle position sensor *6. Idle switch *7. No.1 cylinder TOC sensor *8. Cronk angle sensor *9. MOlor position sensor.'0. Atmospheric pressure sensor Ignition switch ST Power supply. Vehicle-speed sensor Air conditioner switch Inhibitor swilch(ait only) INPUT * 1. Injector * 2. ISC servo * 3. Purge control solenoid valve Fuel pump control (control relay). Air conditioner power relay Ignition timing control ToC Top Dead Center All : Vehicles witch automatic Iransaxle AIR CLEANER MRomE., POSITION AIR FLOW SENSOR (TPSI SENSOR (AFS) "0 ATMOSPHERIC ~,"~T"==~lV'PRESSURESENSOR (FOR AIR CONI OIS~TRIBUTOR CRA"K "SANGlE SENSOR *711'1 CYl TOC AIRINLET '3 AIR TEMP SENSOR ISC MOTOR *' l'i~~?iiii~thermo VALVE TWC PCV : Positive Crankcase Ventilation TWC : Three-way Catalytic Converter 31Y032 29-7

SCHEMATIC DRAWING (FOR CALIFORNIA) GENERAL.1. Ol(ygeo sensor *2. Air-flow sensor *3. Intake air temperature sensor *4. Coolanl temperature sensor *5. Throttle pashian sensor *6. Idle switch *7. NO.1 cylinder TOC sensor *8. Crank angle sensor *9. Motor position sensor.10. Atmospheric pressure sensor IgnitIon switch-s1 Power supply. Vehicle-speed sensor. Air conditioner switch Inhibitor sw;tch(a/t only) *11. EGR temperature sensor *1. Injector *2. ISC servo *3. Purge control solenoid valve *4. EGA solenoid valve Fuel pump control (control relay) Air conditioner power relay Ignition liming COnlrol TOC Top Dead Center AIT : Vehicles witch automatic Iransaxle '2 AlA FLOW., THROTIlE POSITION SENSOR (TPS) SENSOR IAF71 :i~ospheric IDLE POSITION SW ~ "'PRESSU:E~S~EN~'~O~R~_~,BAfb~~E~~~/,g==='1 ~ ~\..n.~ AIR INLET ~. \ 1 l' ~lr------~v==~(~pi;;~ AIR CCEANER-_ '3 AIR TEMP SENSOR j' j *2 ISC MOTOR tfor AIR-CON) I EGR VALVE DI(YdSTRIBUTOR :1~HoRI POSITION ~ ='-ilc~~~~~~i1~s;e;n;s;;o;r~~=ll=r:~~~~~~l=li=r==' ~:~elpump CRANK *8ANGlE SENSOR :: -*7/1'1 CVL TOC SENSOR PURGE CONTROL SO ENOIO.., COOLANT TEMP SENSOR EGR." TEMP SENSOR C PCV : Positive Crankcase Ventilation TWC : Three-way Catalytic Converter 31Y033 29-8

CRANKCASE EMISSION CONTROL SYSTEM CRANKCASE EMISSION CONTROL SYSTEM COM PO N ENTS Air Filter Air Intake Hose Throttle Body ~------\-,-----~ \ Surge Tank -- pev Valve --- _... Injector Ventilation Hose l=:::iln~take Manifold Blow-by Gas -----.. Fresh Air From Rocker Cover~ " " ~ To Intake Manifold ~~~ Plunger Spring 29Y017 INSPECTION Y29DAOA 1. Disconnect the ventilation hose from the positive crankcase ventilation (PCV) valve. Remove the PCV valve from the rocker cover and reconnect it to the ventilation hose. 2. Run the engine at idle and put a finger on the open end of the PCV valve and make sure that intake manifold vacuum is felt. NOTE The plunger inside the PCV valve will move back and forth. 3. If vacuum is not felt, clean the PCV valve and ventilation hose in cleaning solvent or replace if necessary. 29-9

CRANKCASE EMISSION CONTROL SYSTEM PCV Valve Operating,.-, Intake manifold side ~ n (No vacuum) Intake manifold side (High vacuum) I f------' lr Rocker cover side \ 29Y019 ~ t '-- Ir Rocker cover side Engine condition Not running Engine condition Idling or decelerating PCV valve Not operating PCV valve Fully operating Vacuum passage Clogged Vacuum pass~ge Small rtf Intake manifold side (Moderate vacuuml mr ~ I n Intake manifold side (Low vacuum) 29Y020 \ ffif Rocker cover side \ 29V021 ~ Ir Rocker cover side Engine condition Normal operation Engine condition Accelerating and high load PCV valve Properly operating PCV valve Slightly operating Vacuum passage Large Vacuum passage Much larger 29Y022 29-10

EVAPORATIVE EMISSION CONTROL SYSTEM EVAPORATIVE EMISSION CONTROL SYSTEM COMPONENTS Air filter \ Overfill limiter (2-way valve) Fuel injector Engine Canister Purge-control solenoid I valve : t Charcoal-H~h Thermal expansion volume l Fuel gauge unit Fuel filler cap (Vacuum relief) Overfill limiter (Leveling pipe),-,,,,, - Filter Fuel pump --- - Purge air Fuel vapour 29Y023 CANISTER Y29EAOA When the engine is not running, fuel vapours generated inside the fuel tank are absorbed and stored in canister. When the engine is running, the fuel vapours contained in canister are drawn into the surge tank through the pu'ge control solenoid valve. To purge control valve ~ Charcoal ~ Vapour from fuel tank wf(t;~~~~ 29Y024 29-11

EVAPORATIVE EMISSION CONTROL SYSTEM Inspection 1. Look for loose connections, sharp bends or damage in the fuel vapour lines. 2. Look for deformation, cracks or fuel leakage. 3. After removing the charcoal canister, inspect for cracks or damage. 29Y025 PURGE CONTROL SOLENOID VALVE Y29EBOA The purge control solenoid valve is controlled by the ECU; when the engine coolant temperature is low, and also during idling, the valve closes so that evaporated fuel is not drawn into the surge tank. After engine warm-up, during ordinary driving, it opens to let stored vapors into the surge tank. To canister To throttle body.- ;:::::~~][r/ "- ;:::::~~l.v 29Y026 Inspection NOTE When disconnecting the vacuum hose. make an identification mark on it so that it can be reconnected to its original position. 1. Disconnect the vacuum hose (black with red stripe) from the solenoid valve. 2. Detach the harness connector. 3. Connect a manual vacuum pump to the nipple to which the red-striped vacuum hose was connected. 4. Apply vacuum and check when voltage is applied to the purge-control solenoid valve and when the voltage is discontinued. Battery voltage When applied When discontinued Normal condition Vacuum is released. Vacuum is maintained. 29Y028 29-12

EVAPORATIVE EMISSION CONTROL SYSTEM 5. Measure the resistance between the terminals of the solenoid valve. Purge control solenoid valve Coil resistance 36-44!1 [at 20 C (68 F)] 29Y029 OVERFILL LIMITER (TWO-WAY VALVE) Y29ECOA The overfill limiter consists of a pressure valve and a vacuum valve. The pressure valve is designed to open when the fuel tank internal pressure has increased over the normal pressure and the vacuum valve opens when a vacuum has been produced in the tank. To fuel check valve Pressure valve 29YOJO FUEL CHECK VALVE Y29EDQA The fuel check valve is used to prevent fuel leaks when the car suddenly rolls over. This valve is connected in the fuel vapour line (between canister and overfill limiter) and is installed on the fuel tank. The fuel check valve contains two balls as shown in the illustration. Under normal conditions, the gasoline vapour passage in the valve is opened, but if roll-over occurs, one of the balls closes the fuel passage, thus preventing fuel leaks. To overfill limiter From fuel tank " 29YQJl 29-13

EVAPORATIVE EMISSION CONTROL SYSTEM FUEl FILLER CAP The fuel filler cap is equipped with a vacuum relief valve to prevent the escape of fuel vapour into the atmosphere. Atmospheric pressure Fuel vapour pressure Fuel tank vacuum When pressure is in fuel tank When vacuum is in fuel tank 29Y032 CHECKING PURGE CONTROL SYSTEM Thronle body,.. :t- Purge control solenoid valve '" Surge tank Control relay 1 = ECU Air-flow sensor Coolant temperature sensor Intake air temperature sensor Air conditioner switch I 29Y033 29-14

EVAPORATIVE EMISSION CONTROL SYSTEM Checking Y29EEOA 1. Disconnect the vacuum hose (red stripe) from the throttle body, and connect a manual vacuum pump to the vacuum hose. I r- ---~--J::::\J r o F Y-C1\\\ ' 29Y098 2. Check the following points when the engine is cold [coolant temperature 60 e 0 (140 F) or below] and when it is warm [coolant temperature 70 e 0 (158 F) or higher]. When engine is cold Engine operating condition Idling 3,000 rpm Applying vacuum Result When engine is warm Engine operating condition Apply vacuum Result Idling 50 kpa (7.3 psi) Vacuum is maintained Within 3 minutes Try applying vac- Vacuum is released after engine start uum 3,000 rpm After 3 minutes 50 kpa (7.3 psi) Vacuum will be mainhave passed after tained momentarily, engine start a!ter which, it will 3,000 rpm be released. 29-15

EXHAUST EMISSION CONTROL SYSTEM EXHAUST EMISSION CONTROL SYSTEM EXHAUST EMISSION CONTROL SYSTEM Y29FAOA Exhaust emissions (CO, HC, NOx) are controlled by a combination of engine modifications and the addition of special control components. Modifications to the combustion chamber, intake manifold, camshaft and ignition system form the basic control system. Additional control devices include a jet air system, an exhaust gas recirculation (EGR) system and catalytic converters. These systems have been integrated into a highly effective system which controls exhaust emissions while maintaining good driveability and fuel economy. JET AIR SYSTEM Y29FBOA, In addition to the intake valve and exhaust valve, a jet valve has been provided for drawing jet air into the combustion chamber. A jet air passage is provided in the throttle body, intake manifold and cylinder head. Air flows through the two intake openings provided near the throttle valve of the throttle body, goes through the passage in the intake manifold and cylinder head, and flows through the jet valve and the jet opening into the combustion chamber. The jet valve is actuated by the same cam as the intake valve and by a common rocker arm so that the jet valve and intake valve open and close simultaneously. The jet air flowing out of he jet valve scavenges the residual gases around the spark plug and creates an ideal ignition condition. It also produces a strong swirl in the combustionchamber which continues through out the compression stroke and improves flame propagation after ignition, assuring high combustion efficiency. Intake valve 29Y035 AIR/FUEL MIXTURE RATIO CONTROL SYSTEM [Multi Point Injection (MPI) System] V29FCOA The MPI system is a system which employs the signals from the oxygen sensor to activate and control the injector installed in the manifold for each cylinder, thus precisely regulating the air/fuel mixture ratio and reducing emissions. This in turn allows the engine to produce exhaust gases of the proper composition to permit the use of a three-way catalyst. The three-way catalyst is designed to convert the three pollutants (1) hydrocarbons (He), (2) carbon monoxide (CO), and (3) oxides of nitrogen (NOx) into harmless substances. There are two operating modes in the MPI system. 1. Open Loop-air fuel ratio is controlled by information programmed into the ECU at manufacture. 2. Closed Loop-air fuel ratio is varied by the ECU based on information supplied by the oxygen sensor. 29-16

EXHAUST EMISSION CONTROL SYSTEM CATALYTIC CONVERTER Y29FDOA Supporter Exhaust air.. Cover Stainless steel 29YOJ6 The three-way catalytic converter which is a monolithic type with catalytic compositions applied to the integrally constructed honey -comb carrier surface installed in the center of the exhaust pipe. The converter working in combination with the air-fuel ratio feed -back control oxidizes CO and HC and reduces NOx. Function The three-way catalytic converter removes CO, HC and NOx most effectively in the vicinity of the theore!ical air-fuel ratio. The air -fuel mixture to the theoretical air-fuel ratio and the catalytic converter promotes both oxidation and reduction of resultant exhaust gas to make it clean before it is released to atmosphere. CAUTION The catalytic converters require the use of unleaded gasoline only. Leaded gasoline will destroy the effectiveness of the catalysts as an emission control device. Under normal operating conditions, the catalytic converters will not require maintenance. However, it is important to keep the engine properly tuned. Engine misfiring may cause overheating of the catalysts. This may cause heat damage to the converters or vehicle components. This situation can also occur during diagnostic testing if any spark plug cables are removed and the engine is allowed to idle for a prolonged period of time. 1()() _.._."~ HC.1 /j / Vicinity (%) 50./ 0.' \ CO... I Theoretical air-fuel ratio 29Y037 29-17

EXHAUST EMISSION CONTROL SYSTEM EXHAUST GAS RECIRCURATION SYSTEM Y2"'08 Inspection (For Federal. Canada) 1. Disconnect the vacuum hose (green stripe) from the throttle body, and connect a vacuum pump to the vacuum hose. 2. Check the following points when the engine is cold [coolant temperature 50 C (122 F) or below] and when it is hot [Coolant temperature BQ-95 C (176-205 F) or higher]. Engine coolant Engine Normal Vacuum temperature condition condition \ 29Y099 Cold Apply Idling Vacuum is released Hot 6 kpa Idling Vacuum is (1.7 in.hg) held 26 kpa Idle is Vacuum is (7.5 in.hg) unstable held Inspection (For California) 1. Disconnect the vacuum hose (green stripe) from the EGR valve, and connect a vacuum pump via the three way terminal. 2. Check the following points when the engine is cold [Coolant temperature 20 C (6BOF) or below] and when it is hot [Coolant temperature 70 C (15BOF) or higher]. When the engine is cold Engine condition Press the accelerator pedal suddely and race the engine. Normal condition Vacuum: no change (atmospheric pressure) When the engine is warm Engine condition Normal condition Press the accelerator pedal Vacuum rises temporarily suddenly and race the to 14 kpa (3.9 in.hg). engine. 3. Disconnect the three-way terminal and connect the hand vacuum pump directly to the exhaust gas recirculation (EGR) valve. 4. Check whether the engine stalls or the idling is unstable when a vacuum of 20 kpa (5.9 in.hg) or higher is applied during idling. 29-18

EXHAUST EMISSION CONTROL SYSTEM EGR Valve 1. Removethe EGR valve and check it for sticking. carbon deposits, etc. If such conditions exist, clean with solvent to ensure tight valve seat contact. 2. Connect a vacuum pump to the EGR valve. 3. Apply a vacuum of 67 kpa (19.6 in.hg) and check that vacuum is held. 4. Blow in air from one passage of the EGR and check as follows. 29Y()41 Vacuum Normal condition 6 kpa (1.7 in.hg) or less Air does not blow through 26 kpa (7.5 in.hg) or more Air blows through NOTE When installing the EGR valve. use a new gasket and tighten to the specified torque. Tightening torque EGR~I~. 19-27 Nm (190-280 kg.cm. 14-20 Ib.lt) EGR Temperature Sensor (California Vehicles Only) 1. Place the EGR temperature sensor in water. and then measure the resistance value between terminals 1 and 2 while increasing the water temperature. If out of specification, replace the EGR temperature sensor. Temperature C (OF) 50 (122) 100 (212) Resistance (Kn) 60-83 11-14 50n5\1_... 2 if CJ 'Y -. ( ) - - - - - - - - ~, 29Y089 Tightening torque EGR temperature sensor... 10-12 Nm (100-120 kg.cm, 7.3-8.6Ibft) 29-19

EXHAUST EMISSION CONTROL SYSTEM Thermo Valve (Federal. Canada Vehicles Only) NOTE 1} Do not use a wrench on the plastic section when removing or installing the thermo valve. 2) When installing. apply a coating of sealant to the thraads. and tighten to the spacified torque. Tightening torque Thermo valve. 20-39 Nm (200-400 kg.cm. 14-29 Ib.lt) 3) When disconnecting the vacuum hose. make an identification mark on it so it can be reconnected to the original position. 1. Disconnect the vacuum hoses (yellow stripe and green stripe) from the thermo valve. and connect a vacuum pump to the thermo valve. 2. Apply vacuum and check the air passage through the thermo valve. Engine coolant temperature 50 C (122 F) or less 80 C (176 F) or more Normal condition Vacuum is released Vacuum is held EGR Control Solenoid Valve (California) NOTE When disconnecting the vacuum hose. make an identification mark on it so that it can be reconnected to the original position. 1. Disconnect the vacuum hoses (green stripe) from the solenoid valve. 2. Disconnect the harness connector. 3. Connect a vacuum pump to the nipple to which the green-striped vacuum hose was connected. 4. Apply a vacuum and check for air-tightness when voltage applied directly to the EGR control solenoid valve when the voltage is discontinued. Battery voltage When applied When discontinued Result Vacuum is held. Vacuum is released. r EEl,..I, e = ar;:: -=:, :!U..I 5. Measure the resistance between the terminals of the 12V solenoid valve. Standard value: 36-44!1 [at 20 0 e (68 F)] 29Y091 29-20