ENGINE—5S–FE ENGINE
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ENGINE 5S–FE ENGINE DESCRIPTION The 5S–FE engine is designed on the basis of the dependable 3S–FE engine, but has a larger piston displacement to deliver increased torque in all ranges. The 3S–FE engine is discontinued in the new line–up.
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ENGINE SPECIFICATIONS AND PERFORMANCE CURVE Engine
5S FE 5S–FE
3S FE 3S–FE
No. of Cyls. & Arrangement
4–cylinder, In–line
←
Valve Mechanism
4 Valves, DOHC, Belt & Gear Drive
←
Pentroof Type
←
Cross–flow
←
132.0 (2164)
121.9 (1998)
3.43 x 3.58 (87 x 91)
←
9.5 : 1
9.3 : 1
Item
Combustion Chamber Manifolds Displacement
cu. in. (cc)
Bore x Stroke
in. (mm)
Compression Ratio Max. Output
(SAE–NET)
130 HP @ 5400 rpm
115 HP @ 5200 rpm
Max. Torque
(SAE–NET)
140 ft.lbs @ 4400 rpm
124 ft.lbs @ 4400 rpm
91
←
API SG
API SF or SG
Fuel Octane Number Oil Grade
(RON)
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ENGINE 1. Cylinder Head The squish area in the combustion chamber was redesigned to further improve the engine’s high–speed performance. The new engine has a part of the squish area around the intake valve area removed to reduce intake air resistance.
2. Cylinder Head Bolts and Gasket Plastic region–tightening bolts are used to improve sealing integrity of the cylinder head gasket. The cylinder head gasket is made out of graphite fibers, a new industrial material known for outstanding heat resistance. Sealing performance is further enhanced by addition of wire rings around bore grommets and o–rings in the blow–by gas holes and oil return holes.
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3. Cylinder Block To coincide with the increase in the piston displacement, the cylinder block skirt was redesigned and the bore wall was made thicker than in the previous engine. The right–side mounting bracket area, block–to–transmission joint, etc., were reinforced to further reduce vibration and noise.
The crankshaft bearing area is made more rigid to suppress the crankshaft radial movement and thus further reduce transmitted noise.
4. Piston and Piston Rings The semi–floating piston pin of the 3S–FE engine was replaced with full–floating pin in the new 5S–FE engine. The piston pin diameter was increased from 0.79 in. to 0.87 in. (from 20 to 22 mm) to further increase the pin rigidity.
The overall piston weight was reduced by redesigning the piston skirt without affecting its rigidity.
5. Crankshaft The crankshaft of the new 5S–FE engine is made of forged iron (cast iron in the 3S–FE engine). Furthermore, the pin diameter was increased from 1.89 to 2.05 in. (from 48 to 52 mm) to drastically improve rigidity.
ENGINE—5S–FE ENGINE
6. Connecting Rod and Connecting Rod Bearings The connecting rod is hot–forged type. The connecting rod bearing cap is fastened with plastic region bolts.
To coincide with the new connecting rod, the connecting rod bearing is made of highly heat–resistance kelmet alloy.
7. Flywheel The crankshaft is fastened by 8 bolts to further increase reliability.
VALVE MECHANISM Valve Timing The valve timing was changed as shown below to further improve performance.
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ENGINE—5S–FE ENGINE
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LUBRICATION SYSTEM Oil Cooler An oil cooler is installed in the GT–S with manual transmission.
COOLING SYSTEM General
The diameter of the thermostat was increased from 1.18 to 1.38 in. (from 30 to 35 mm) to more efficiently cool the engine around the port area in the cylinder head and around spark plugs.
The radiator tube design was changed to optimize flow and the fin shape was reviewed in order to further improve cooling performance and reduce the overall weight.
INTAKE SYSTEM Resonator A resonator is fitted to the air intake hose to reduce intake air noise.
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ENGINE MOUNTING 1. General The new 5S–FE engine is mounted at four points the same as 3S–FE engine. A newly–developed, cylindrical, liquid–filled compound mount is used at the left and right sides to reduce the engine noise and vibration.
The right–hand mounting bracket is made of aluminum to reduce weight and increase rigidity. A stay is added to left and right mounts and a dynamic damper is added to the right–hand mount to further reduce vibration and noise.
2. Cylindrical Liquid–filled Compound Mount The newly–developed, cylindrical, liquid–filled compound mount has an insulator filled with a fluid. The fluid inside the fluid chamber reduces the dynamic spring modulus in the high–frequency range and thus increases quietness in the passenger compartment. The flow of fluid through the orifice increases the damping coefficient and thus suppresses the engine vibration.
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ENGINE CONTROL SYSTEM 1. General The engine control system for the 5S–FE engine is similar to the 3S–FE engine. However, the D–type EFI system has been adopted along with the EGR cut–off control system. The engine control system is matched to the 5S–FE engine. The following table gives a comparison between the engine control system for the 5S–FE engine and 3S–FE engine. Engine
5S FE 5S–FE
System
3S FE 3S–FE
A D–type EFI system is used which An L–type EFI system is used which EFI (Electronic Fuel Injection)
indirectly detects intake air volume by the manifold pressure sensor signal. The fuel injection system is simultaneously an all injection system (one injection per engine revolution).
directly detects the intake air volume with a vane type air flow meter.
Ignition timing is determined by the ECU based on signals from various sensors. ESA (Electronic Spark Advance)
In vehicles equipped with automatic transaxle, the torque control compensation during gear shifting has been used to minimize the shift shock (only A241E A/T).
←
← N.A.
ISC (Idle Speed Control)
A rotary solenoid type ISC system is used, which controls the fast idle and idle speeds.
←
EGR Cut–Off Control
By controlling the EGR–VSV in accordance with the coolant temperature or engine speed, drivability of the vehicle and durability of the EGR components is maintained.
N.A.
Fuel Pump Control
Fuel pump operation is controlled by signals from ECU based on the engine speed signal (Ne).
Fuel pump operation is controlled by signals from air flow meter.
Air Conditioner Cut–Off Control
By controlling the air conditioner compressor in accordance with the throttle valve opening angle and the vehicle speed, drivability is maintained.
By controlling the air conditioner compressor in accordance with the throttle valve opening angle, the vehicle speed and drivability is maintained.
When a malfunction occurs, the ECU Diagnosis
Fail–Safe
diagnoses and memorizes the failed section. 13 diagnostic items (15 for California) are monitored by the ECU.
When a malfunction occurs, the ECU stops or controls the engine according to the data already stored in memory.
←
14 diagnostic items (16 for California) are monitored by the ECU. ←
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Engine control system for the 5S–FE engine has the following functions: EFI (Electronic Fuel Injection) The ECU determines the fuel injection duration according to the intake manifold pressure, engine speed, coolant temperature and other signals, then sends control signals to the fuel injectors. The fuel injection duration is also the basis for deciding the fuel injection timing. The fuel injection system is simultaneously an injection system. ESA (Electronic Spark Advance) The ECU determines the amount of ignition advance in addition to the initial timing based on the intake manifold pressure, engine speed, coolant temperature and other signals, then sends control signals to the igniter. In vehicles equipped with automatic transaxle the ignition timing is delayed in accordance with the shift positions during all shifting to control the engine output temporarily and reduce shift shock (only A241E A/T). ISC (Idle Speed Control) By means of engine speed signals, the ECU sends control signals to the ISC valve to maintain actual idle speed at the target idle speed stored in the ECU. Also, while the engine is warming up, the ECU, based on coolant temperature signals, sends controls signals to the ISC value to increase engine speed to fast idle. EGR Cut–Off Control The ECU sends a signal to the EGR VSV to shut–off the EGR according to the coolant temperature, engine speed and intake manifold pressure. This helps to maintain drivability of the engine under cold temperature and at high engine rpm, and durability of EGR components. Fuel Pump Control Normally, the ECU controls the operation of the fuel pump based on the engine speed signal detected by the distributor. While the engine is cranking, however, the ST signal from the ignition switch controls the fuel pump. Air Conditioner Cut–Off Control The ECU sends control signals to the air conditioner amplifier base don the throttle position, vehicle speed and air conditioner switch signals to shut–off the air conditioner compressor temporarily to maintain drivability while the air conditioner is operating. Diagnosis The ECU is constantly monitoring signals from each sensor. If trouble develops with the signals, the CHECK ENGINE lamp inside the meter panel lights up and informs the driver of the malfunction. The contents of the trouble codes are stored in ECU memory and when the T and E1 terminals in the check connector are connected, the ECU outputs the trouble code by flashing the CHECK ENGINE lamp. Fail–Safe If the ECU judges from the signals from each sensor that there is a malfunction, it will continue the engine operation, using its own data or it will stop the engine.
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2. Construction The engine control system can be broadly divided into three groups; the sensors, the ECU and the actuators.
*1: Applicable only to A241E automatic transaxle models. *2: Applicable only to California specification vehicles. *3: Refer to page 115 for detail.
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ENGINE—5S–FE ENGINE
3. Engine Control System Diagram
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ENGINE—5S–FE ENGINE
4. Arrangement of Engine Control System Components
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5. Construction and Operation of Main Components Distributor The conventional distributor (having a built–in coil) used on the 3S–FE engine was replaced with a separate coil type distributor in the new 5S–FE engine. The diameter of the high–tension cord was changed from 0.28 to 0.20 in. (from 7 to 5 mm) to reduce weight. The new distributor’s basic function remains the same as the previous model.
Manifold Pressure Sensor To coincide with the addition of the D–type EFI system, a manifold pressure sensor is now fitted to the intake system of the new engine. The sensor is built and operates basically the same as in the 4A–FE engine for the Corolla All–Trac/4WD station wagons (’89 model AE95 series).
ENGINE—5S–FE ENGINE
82 Throttle Position Sensor
Two types of throttle position sensors (point type and linear type) are used in the 5S–FE engine, and used selectively according to the transaxle type. Transaxle Type Manual Transaxle (S53) Automatic Transaxle (A241L) Automatic Transaxle (A241E) Point Type
Linear Type
Throttle Position Sensor Point Type Linear Type
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6. EFI (Electronic Fuel Injection) General The EFI system consists of three sub–systems as in the 3S–FE engine; the fuel, air induction and electronic control sub–systems. All of the three systems were modified to match the new 5S–FE engine. Fuel System The fuel injectors have two holes as in the previous model, but the moving parts were modified to make the injector more compact and lightweight and further reduce the minimum operating voltage. The injector volume was increased to match the higher output.
Air Induction System 1) Throttle Body The ISC valve is integrated into the throttle body to reduce the overall weight.
ENGINE—5S–FE ENGINE
84 Electronic Control System 1) Injection Duration Control
The ECU determines the duration of each injection cycle in three steps as shown below, the same as in the 3S–FE engine. Step 1: Determination of Basic Injection Duration Step 2: Determination of Adjusted Injection Duration Step 3: Determination of Length of Injection Signal The EFI in the 5S–FE engine controls step three in the same way as the EFI in the 3S–FE engine, but due to the adoption of the D–type EFI system which uses a manifold pressure sensor, the methods of determining the “basic injection duration” in Step 1, and or “acceleration enrichment” and “power enrichment” in Step 2, have been changed.
a. Basic Injection Duration Determined The basic injection duration is determined by the manifold pressure (PIM signal) and the engine speed (Ne signal). The internal memory of the ECU contains data of various basic injection durations for various manifold pressures and engine speeds.
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b. Acceleration Enrichment The ECU sends signal to the injector to inject extra fuel during acceleration in order to maintain drivability. The ECU detects engine acceleration conditions based on the manifold pressure changes.
RELEVANT SIGNALS
Intake manifold pressure (PIM) Throttle position (IDL) Coolant temperature (THW) Engine speed (Ne)
c. Power Enrichment When the ECU determines from the throttle position and intake manifold pressure that the injection duration is in the power range, it increases the injection volume according to engine conditions at that time in order to maintain good drivability.
RELEVANT SIGNALS
Intake manifold pressure (PIM) Throttle position (PSW or VTA) Engine speed (Ne)
2) Fuel Cut–Off Fuel cut–off during deceleration is carried out in the same way as in the 3S–FE engine. The fuel is also cut at an engine speed of 6500 rpm to prevent engine overrunning.
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7. ESA (Electronic Spark Advance) General The principles of ignition timing control are the same as in the 3S–FE engine. However, with the adoption of the D–type EFI system, the method for calculating the basic ignition advance angle when the IDL contacts are open has been changed. Also, for vehicles equipped with A241E automatic transaxle, torque control compensation is added to minimize the shift shock when shifting. Determination of Basic Ignition Advance Angle The basic ignition advance angle when the IDL contacts are closed is determined by the ECU from the engine speed, same as in the 3S–FE engine. When the IDL contacts are open, the most appropriate basic ignition advance angle is selected by the ECU from basic ignition advance angle data stored in the ECU. This data is determined in accordance with the engine speed and intake air volume in the case of the L–type EFI system in the 3S–FE engine, but in the D–type EFI system in the 5S–FE engine, it is determined in accordance with the engine speed and intake manifold pressure. Basic Ignition Advance Angle Data RELEVANT SIGNALS
Intake manifold pressure (PIM) Engine speed (Ne) Throttle position (IDL)
Torque Control Compensation During Shifting (Only A241E A/T) In the case of vehicles equipped with A241E automatic transaxle, each clutch and brake of the planetary gear unit in the transaxle generates shock more or less during shifting. In the 5S–FE engine, this shock is minimized by delaying the ignition timing when gears are shifted in the automatic transaxle. The ECU judges the vehicle’s condition by engine speed and torque converter turbine runner speed, then determines the optimum amount of ignition timing delay from gear shifting mode (1→2, 2→3, 3→4, 4→3, 3→2, 2→1) and the throttle valve opening angle. This compensation is not performed at times when the coolant temperature is below 140°F (60°C), when the battery terminal voltage is below 8V, or when the No. 2 shift solenoid valve in the automatic transaxle is malfunctioning.
RELEVANT SIGNALS
Engine speed (Ne) Vehicle speed (SP2) Throttle position (VTA) Coolant temperature (THW) Gear shift position (S1, S2) Battery (+B)
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8. ISC (Idle Speed Control) General The rotary solenoid type ISC valve of the 3S–FE engine is retained for the 5S–FE engine. Although the basic valve construction and operation remain unchanged, a feedback control is added in the new engine for the air conditioner feature and the valve is made more compact and lightweight.
Feedback Control During Air Conditioner Operation When the ECU receives a signal from the air conditioner amplifier, it opens the ISC valve to increase idle speed. At the same time, it begins feedback control at a target idle speed for air conditioner operation.
RELEVANT SIGNALS
Engine speed (Ne) Throttle position (IDL) Vehicle speed (SPD) Coolant temperature (THW) Neutral start switch (NSW) Air conditioner switch (A/C)
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9. EGR Cut–Off Control This system actuates the VSV to replace intake manifold vacuum acting on the EGR vacuum modulator with atmospheric air and thus shuts off the EGR. Operation The ECU actuates the VSV and cuts the EGR from the system when the coolant temperature is below 140°F (60°C) or the engine speed is about 4400 rpm to maintain drivability. The ECU also actuates the VSV and cuts the EGR from the system when the intake manifold pressure is above a predetermined level to maintain durability of the EGR components.
10.Fuel Pump Control See page 64 under 3S–GTE engine for detail.
11.Air Conditioner Cut–Off Control See page 65 under 3S–GTE engine for detail.
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12.Diagnosis The diagnostic system in the new 5S–FE engine monitors thirteen conditions (fifteen for California) in the chart below. The purpose of this system is the same as for the current 3S–FE engine, but diagnostic items have been changed to match the 5S–FE engine. Diagnostic Items Code No.
12
13
14
21
22
24
25
Item
RPM Signal
RPM Signal
Ignition Signal
Diagnosis
No “Ne” or “G” signals to ECU within 2 seconds after the engine is cranked.
No “Ne” signal to ECU when the engine speed is above 1000 rpm.
No “IGf” signal to ECU 45 times in succession.
Oxygen Sensor Signal
During air–fuel ratio feedback correction, voltage output from the oxygen sensor does not exceed a set value on the lean side and the rich side continuously for a certain period.
Water Temp. Sensor Signal
Open or short circuit in water temp. sensor signal (THW).
Intake Air Temp. Sensor Signal
Air–fuel Ratio Lean Malfunction
Open or short circuit in intake air temp. sensor signal (THA).
1)* When air–fuel ratio feedback correction value or adaptive control value continues at the upper (lean) or lower (rich) limit for a certain period of time or adaptive control value is not renewed for a certain period of time. 2)* When marked variation is detected in engine revolutions for each cylinder during idle switch on and feedback condition. 3) Open or short circuit in oxygen sensor signal.
26
27*
31
Air–fuel Ratio Rich Malfunction
Sub–Oxygen Sensor Signal
Manifold Pressure Sensor Signal
Open or short circuit in sub–oxygen sensor signal.
Open or short circuit in manifold pressure sensor signal.
41
*:
Throttle Position Sensor Signal
Open or short circuit in throttle position sensor signal (VTA). → For A241E A/T. The “IDL” and “PSW” signal are output simultaneously for several seconds. → Except A241E A/T.
Applicable only to California specification vehicles.
Trouble Area
“CHECK ENGINE” Lamp
Distributor circuit Distributor
ON
Starter signal circuit ECU Distributor circuit ON
Distributor ECU Igniter circuit
ON
Igniter ECU Oxygen sensor circuit
ON
Oxygen sensor Water temp. sensor circuit ON
Water temp. sensor ECU Intake air temp. sensor circuit
ON*
Intake air temp. sensor ECU Injector circuit Injector Fuel line pressure Oxygen sensor circuit
ON*
Oxygen sensor Intake manifold pressure Water temp. sensor
ON
ECU Injector circuit Injector ON*
Intake manifold pressure Water temp. sensor ECU Sub–oxygen sensor circuit Sub–oxygen sensor
ON
ECU Manifold pressure sensor circuit Manifold pressure sensor
ON
ECU Throttle position sensor circuit Throttle position sensor ECU
ON*
ENGINE—5S–FE ENGINE
Code No.
Item
Vehicle Speed Sensor Signal
42
43
Starter Signal
EGR System Malfunction
71*
Switch Condition Signal
51
*:
90
Diagnosis No “SP1” signal to ECU for 8 seconds when engine speed is between 2400 rpm and 5000 rpm and coolant temp. is above 176°F (80°C), except when racing the engine.
No “STA” signal to ECU until engine speed reaches 800 rpm with vehicle not moving.
EGR gas temp. below a predetermined level during EGR operation. Open circuit in EGR gas temp. sensor signal (THG).
No “IDL” signal or No “NSW” signal or “A/C” signal to ECU, with the check terminals T and E1 connected.
Trouble Area
“CHECK ENGINE” Lamp
No. 1 vehicle speed sensor circuit No. 1 vehicle speed sensor
OFF
ECU Starter signal circuit Ignition switch, main relay circuit
OFF
ECU EGR system components EGR gas temp. sensor circuit
ON
EGR gas temp. sensor ECU A/C amplifier A/C switch circuit Neutral start switch circuit Neutral start switch
OFF
Throttle position sensor circuit Throttle position sensor Accelerator pedal and cable ECU
Applicable only to California specification vehicles.
NOTE:
If two or more malfunctions are present at the same time, the lowest–numbered diagnostic code will be
displayed first. All detected diagnostic codes, except 51, will be retained in memory by the ECU from the time of detection until cancelled out. Once the malfunction is corrected, the “CHECK ENGINE” warning lamp will go out but the diagnostic code(s) will remain stored in the ECU memory (except for code 51). After the malfunction is corrected, the diagnostic code is cleared by removing the EFI fuse for more than 10 seconds with the ignition switch off.
13.Fail–Safe The fail–safe function of the 3S–FE engine is also used in the new 5S–FE engine plus the following additional function. Manifold Pressure Sensor Malfunction The air–fuel ratio deviated from normal if the signal from the pressure sensor is open or shorted, causing improper engine running. In this case, a back–up mode operates and maintains the ignition timing and fuel injection timing at fixed values to continue operation.
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EMISSION CONTROL SYSTEM 1. System Purpose System
Abbreviation
Purpose
Positive crankcase ventilation
PCV
Reduces blow–by gas (HC)
Evaporative emission control
EVAP
Reduces evaporative HC
Exhaust gas recirculation
EGR
Reduces NOx
Three–way catalyst
TWC
Reduces HC, CO and NOx
Electronic fuel injection
EFI
2. Component Layout and Schematic Drawing
*:
Applicable only to California specification vehicles.
Regulates all engine conditions for reduction of exhaust emissions.
