General information
F3R engines are equipped with a sequential fuel injection system.
Features of the system include:
- 55-channel injection system control unit SIEMENS FENIX 5;
- sequential fuel injection;
- static ignition system;
- solenoid valve controlled by the law of cyclic opening;
- correction of the idle speed depending on the battery voltage, the state of the air conditioning system and electric heating of the windshield and the state of the power steering pressure switch (F3R 728 engine);
- function lamp of the injection system in the instrument cluster;
- diagnostics using the XR25 device.
Fuel is not injected simultaneously into four cylinders. as in a system of simultaneous (classical) injection, and in turn, cylinder by cylinder, at the moment when each of them is in the state of the beginning of the intake stroke. To do this, each fuel injector is connected by a separate channel to the injection system control unit. To determine the intake stroke of each cylinder, the injection system control unit uses signals from two sensors:
- crank angle sensor
- camshaft position sensor.
The crankshaft angle sensor transmits information to the injection system control unit about the crankshaft speed and which cylinder pistons are at TDC.
The camshaft position sensor allows the injection control unit to determine which of the two cylinders whose pistons are at TDC is at the beginning of the intake stroke
If the camshaft position sensor fails, the system goes into «emergency» mode and continues to sequentially inject fuel in the 1-3-4-2 sequence.
At the first injection (when starting the engine) the system randomly activates the fuel injector of the first cylinder at the moment when the pistons of the 1st and 4th cylinders are at TDC. Then there are two possibilities:
- the system correctly identified («guessed right») intake stroke of cylinder 1,
- the system incorrectly identified («wrong by 1 crankshaft revolution») the intake stroke of the 1st cylinder, in this case the engine will run unstably.
The ignition system is designed to ignite the air-fuel mixture in each cylinder at a precisely set point in time. In gasoline engines this is achieved by an electric spark (electrical discharge), created between the spark plug electrodes.
The ignition signal is transmitted by the control unit to the switch, which controls two ignition coils. The vehicle's on-board voltage is converted into high voltage by the ignition coil and supplied to two spark plugs.
The engine control unit
The ECU is a programmed microprocessor with a 55-pin connector. It is installed on the right side of the engine compartment and simultaneously controls the fuel supply to the engine cylinders and the ignition timing.
Brand: Siemens
Pin assignment of the engine control unit connector
Contact no | Assigning Contacts |
1 | — |
2 | «Weight» control unit |
3 | «Weight» control unit |
4 | Nozzle No. 3 control |
5 | - |
6 | Information about turning on/off the air conditioner |
7 | — |
8 | Knock sensor signal |
9 | Power steering hydraulic pressure information |
10 | — |
11 | Diagnostic Test Information (line K) |
12 | Speed sensor signal |
13 | Information for the on-board computer about fuel consumption |
14 | — |
15 | Coolant temperature signal |
16 | Intake manifold air pressure signal |
17 | Lambda sensor signal |
18 | «Weight» Lambda sensor |
19 | Throttle Position Sensor Signal |
20 | Air temperature sensor signal |
21 | — |
22 | — |
23 | — |
24 | + after ignition switch |
25 | Nozzle No. 2 control |
26 | Injection system fault indicator control |
27 | — |
28 | Control of the ignition coil of cylinders No. 1 and 4 |
29 | Control of the ignition coil of cylinders No. 2 and 3 |
30 | Nozzle No. 4 control |
31 | — |
32 | + permanent |
33 | Crankshaft position sensor signal (circuit B) |
34 | Crankshaft position sensor signal (chain A) |
35 | Engine start blocking line |
36 | — |
37 | — |
38 | Diagnostic Test Information (line L) |
39 | — |
40 | — |
41 | — |
42 | Cylinder marking sensor signal |
43 | Engine speed signal for tachometer |
44 | «Weight» knock sensor, coolant temperature and air pressure |
45 | Nutrition «+» 5V for air pressure sensor and throttle position sensor |
46 | «Weight» air temperature sensor and throttle position sensor |
47 | — |
48 | Fuel pump relay control |
49 | — |
50 | Activated carbon canister solenoid valve control |
51 | Lock/enable air conditioning compressor clutch engagement |
52 | Monitoring the operation of the fuel pump relay |
53 | Nozzle No. 1 control |
54 | Idle air control control |
55 | — |
Absolute pressure sensor
The absolute pressure sensor is installed on the rock compartment partition and connected to the intake manifold by a rubber corrugated hose. The sensor transmits voltage to the control unit. Directly proportional to intake manifold pressure Voltage at absolute pressure:
- 0.4 bar - 2.1V
- 0.6 bar - 3.4V
- 0.78 bar - 4.7V
Throttle position sensor
The sensor is attached to the end of the throttle valve axis. It is a potentiometer with a linear dependence, the position of the slider coincides with the position of the throttle valve. A constant voltage of 5 V is supplied to the sensor, and the output voltage is directly proportional to the angle of rotation of the throttle valve.
Mounting position - not adjustable
Resistance (measured between sensor contacts), Ohm:
- between contacts A and B - 1220
- between contacts A and C:
- throttle valve closed - 1120
- throttle valve fully open - 2200
- between contacts B and C:
- throttle valve closed - 2200
- throttle valve fully open - 1320
Crankshaft position sensor
The electromagnetic crankshaft position sensor is installed on the clutch housing. It is located opposite the teeth of the flywheel ring gear, which has 60 teeth, with two teeth being shorter. When teeth pass near the sensor, an electrical signal is generated in it; when there is no signal when teeth pass with a lower height, the control unit determines the position of the crankshaft. This mark is at an angle of 84° (or 14 full teeth) to TDC of the pistons of the 1st and 4th cylinders. The engine control unit determines that TDC is after the 15th tooth after the mark. By counting the number of teeth passing near the sensor, the control unit accurately determines the moment of ignition of the fuel mixture. TDC of the 2nd and 3rd cylinders is located at the 45th tooth after passing the mark near the sensor.
The sensor transmits to the control unit a voltage corresponding to the crankshaft speed.
The position of the sensor and its air gap are not adjustable
Brand: Siemens
Resistance, Ohm — 200±50
Principle of cylinder recognition at the beginning of the intake stroke
Cylinder recognition sensor at the beginning of the intake stroke (Hall Sensor) located on the left side of the cylinder head. The sensor has a narrow slot through which a thin 180°steel segment passes, mounted at the end of the camshaft that controls the intake valves. If there is no steel segment in the sensor slot, 12 V voltage is transmitted to the engine control unit. When a steel segment enters the sensor slot, no voltage is transmitted to the engine control unit
In accordance with the signal transmitted by the sensor, the engine control unit determines in which cylinder the fuel mixture is injected and, based on this information, controls the ignition in the corresponding cylinder. The pistons of the 1st and 4th cylinders are at TDC. If:
- The cylinder recognition sensor signal is 0 V. The 4th cylinder is at the beginning of the intake stroke.
- The cylinder recognition sensor signal is 12 V. The 1st cylinder is at the beginning of the intake stroke.
The pistons of the 2nd and 3rd cylinders are at TDC if:
- - the signal from the cylinder recognition sensor is 0 V. The 3rd cylinder is at the beginning of the intake stroke.
- - the signal from the cylinder recognition sensor is 12 V. The 2nd cylinder is at the beginning of the intake stroke.
Angle position and air gap - not adjustable
Lambda sensor (oxygen concentration sensor)
An electrically heated lambda sensor is installed in the exhaust system in front of the catalytic converter. The lambda sensor transmits a signal with a voltage of 0.1-0.7 V to the engine control unit, depending on the enrichment of the fuel mixture.
The engine control unit does not receive information from the oxygen concentration sensor during the following phases
- when the throttle position sensor transmits information that the throttle valve is fully open;
- when the car accelerates intensively;
- when the accelerator pedal is suddenly released;
- if the oxygen concentration sensor malfunctions;
- if there is a malfunction of the vacuum sensor in the intake manifold.
The fuel mixture enrichment adjustment phase begins to function after a time delay:
- if the accelerator pedal is released if the coolant temperature reaches 35°C;
- when the accelerator pedal is released if the coolant temperature exceeds 15°C.
Time delay of the initial phase as a function of coolant temperature:
- at a temperature of 20°C - max 2 min
- at a temperature of 80°C - max 1 min
Brand and type - Bosch LSH25
Output voltage of the sensor/fuel mixture enrichment at a temperature of 850°C, V
- rich fuel mixture - 0.85
- lean fuel mixture - 0.01
Sensor heater:
- supply voltage, V - 12
- resistance, Ohm — 3 - 15
Knock sensor
The piezoelectric knock sensor is located on the front side of the cylinder block between the spark plugs of cylinders 2 and 3.
The knock sensor transmits a voltage of 0.1 to 0.7 V to the engine control unit
Brand and type - Valeo 2576015A
Coolant temperature sensor
NTC Coolant Temperature Sensor (CTN) installed in the thermostat housing.
Resistance, Ohm:
- at a temperature of 20±1°С - 3060-4045
- at a temperature of 40±1°С —1315—1600
- at a temperature of 80±1°С -300-370
- at a temperature of 90±1°С -210-270
Engine air temperature sensor
Engine air temperature sensor with negative temperature coefficient (CTN) installed on the exhaust duct of the air filter housing.
Resistance, Ohm:
- at air temperature 0°C - 8385-10610
- at air temperature 20±1°С - 3279-3769
- at air temperature 40±1°С - 1373-1555
Fuel pump relay
The fuel pump relay is located in the relay and fuse box on the left side of the engine compartment. The fuel pump relay is controlled by the engine control unit, connecting to «mass» its control circuit. The relay turns on briefly when the ignition is turned on and operates continuously as soon as the engine control unit receives information about the rotation of the crankshaft.
Inertial sensor (switch) blow
Inertial sensor (switch) The shock switch is designed to shut off the electrically driven fuel pump if the vehicle is subject to a significant impact.
If your vehicle does not start after a collision, the crash sensor may have been activated.
The inertial impact sensor is located in the engine compartment. The switch button is protected by an elastic casing.
Speed sensor
Typical speed sensor (Hall Sensor) fixed to the gearbox and powered by a voltage of 12 V. The speed sensor signal is transmitted to the speedometer located in the instrument cluster.
Air conditioning control unit
To prevent engine malfunction when the air conditioning system is turned on, the engine control unit is connected directly to the air conditioning system control unit.
For example, if it is necessary to turn on the air conditioning compressor. Before applying voltage to the compressor, the control unit, using the idle speed regulator, will first increase the engine speed and vice versa. This allows you to compensate for the reduction in crankshaft speed from the additional load created by the compressor.
Information is transferred from the engine control unit to the air conditioning control unit via pins 6 and 51 of the engine control unit connector. Through pin 6, the engine control unit receives information to switch to a faster idle speed and turn off the air conditioning compressor. Through contact 51, the engine control unit sends information to allow or prohibit the start of the air conditioning compressor.
In the following cases, the operation of the air conditioning compressor is switched off or deactivated:
- within 10 seconds after starting the engine;
- when the engine temperature is more than 115°C;
- at high engine speeds, which may cause the air conditioning compressor to spin. those. more than 6000 min-1
Ignition coil
Two identical ignition coils are mounted on the front of the cylinder block. Each ignition coil actually consists of 2 separate high voltage windings that supply a spark to two cylinders each (one to cylinders No. 1 and 4. and the other to cylinders No. 2 and 3). The ignition pulse is applied to two spark plugs at once for each engine cycle, one on the compression stroke, one on the exhaust stroke - the ignition spark on the exhaust stroke has no effect on the operation of the engine and is therefore wasted. The engine control module uses inputs from various sensors to calculate the required ignition timing and ignition coil energy storage time
Brand and type - Magneti Marelli BAE 801
Ignition coil primary winding resistance (between pins 1 and 4 or 2 and 3), Ohm - 1
Resistance of the secondary winding of the ignition coil, Ohm - 8,000
Ignition sequence 1-3-4 -2
Spark plug
Brand and type - Bosch WR8DC04 or Eyquem RC 52 LS
Interelectrode gap of spark plugs, mm - 0.9
Power steering pressure sensor
The power steering pressure sensor is installed at the high pressure output of the power steering pump. When the pressure exceeds a certain value, the sensor transmits a signal to the engine control unit, based on which the engine speed increases to 850 min-1.
Characteristics tested at idle*
Idle speed, min-1 - 850±50
Content of toxic substances in exhaust gases**
CO1 % (1) - no more than 0.5
CO2, % - 14.5
CH, ppm - no more than 100
Lambda, l - 0.97 < l < 1.03
(1) At 2500 min-1 the CO content should be no more than 0.3%
*If the coolant temperature is above 80°C, check at 2500 min-1, then at idle
**Permissible standards for the content of toxic substances in exhaust gases are regulated by local legislation
Consumables
Name | Quantity | Place of application |
Rhodorseal 5661 | Sufficient for lubrication | Holes for installing drive shaft pins |
Loctite FRENBLOC Sealant | Sufficient for lubrication | Brake caliper mounting bolts |
Loctite FRENETANCH Sealant | Sufficient for lubrication | Crankshaft pulley bolt |
MOLYKOTE BR 2 Paste for sealing pipe joints in exhaust gas systems | Sufficient for lubrication | Mounting protrusion on the hub under the central hole of the wheel rim |
Tightening torques, Nm
Cylinder head bolts:
- Stage 1 - tighten to 30
- Stage 2 - tighten to an angle of 50±4°
- Step 3 - Wait 3 minutes and loosen the two center bolts by turning them 180°
- Stage 4 - tighten the two central bolts to a torque of 25 Nm and then tighten to an angle of 123±7°
- Stage 5 - loosen the bolts, except for the two central ones
- Stage 6 - tighten the bolts except the two central ones to a torque of 25 Nm and then tighten to an angle of 123±7
Cylinder head cover bolts - 0
Crankshaft pulley mounting bolt - 20 Nm + 115±15°
Main bearing cap bolts - 65
Crankshaft pulley mounting bolt - 50
Camshaft bearing cap bolts:
- bolts M6 - 10
- M8 bolts - 20
Intermediate shaft pulley bolt (F3R 728 engine) — 50
Connecting rod cover bolts - 50
Flywheel mounting bolts - 55
Tension roller bolt - 50
Nuts securing the manifolds to the cylinder head - 20-22
Oxygen concentration sensor - 40
Spark plugs - 25-30
Knock sensor - 25
Cylinder recognition sensor at the beginning of the intake stroke -10
Oil pump mounting bolts - 25
Oil pan mounting bolts - 12-15
Bolt securing the protective cover of the drive shaft - 25
Throttle assembly mounting bolt on the intake manifold - 20
Bolt securing the front right support of the engine pendulum mount to the engine - 50-65
Bolt securing the pendulum suspension to the cylinder head - 20-25
Bolt securing the suspension to the gearbox - 55-65
Bolt for fastening the travel limiter of the front right pendulum suspension - 50-65
Bolts for fastening the lower supports of the shock absorber struts M16x200 - 200
Tie rod mounting bolts - 45-65
Throttle position potentiometer mounting screw - 2
Catalytic converter inlet flange mounting nut - 22
Nut for fastening the front right pendulum suspension bracket - 30-45
Nut securing the bracket cushion of the front right support of the pendulum engine mount - 30-45
Nut securing the pendulum suspension cushion on the front left side member - 55-80
Nut for fastening the repair pipe of the exhaust gas system 25
Fuel distribution line fastening nut - 10
Exhaust system swivel nut - 20
Wheel bolts - 100