15.3. System of injection of fuel

Models of later releases are equipped with system of electronic injection of fuel. It consists of three main systems: food fuel, air supply and electronic control. For service of the system of injection of fuel installed on a part of cars of later releases the special equipment therefore address to the service center can be required.

Power supply system

Fig. 15.11. Power supply system elements fuel: 1 – the fuel filter (on the highway of high pressure); 2 – fuel distributive highway; 3 – nozzle; 4 – tank; 5 – the operating pressure regulator valve; 6 – the filter of the fuel tank (on the soaking-up party); 7 – fuel pump; 8 – three-running distributive valve


The fuel pump with the electric drive located in the fuel tank provides fuel supply under constant pressure to the fuel distributive highway from which fuel is distributed on all four nozzles (fig. 15.11). From the fuel distributive highway fuel is injected by four nozzles into the inlet channels located directly over inlet valves. The portion of injectable fuel is strictly controlled by the microprocessor control unit, the so-called EGI block. The regulator of pressure controls pressure in system according to extent of depression in an inlet collector of the engine. The fuel filter located between the distributive highway and the fuel pump provides protection against pollution of knots of a power supply system with fuel.

System of air supply

Fig. 15.12. System of air supply: and – engines without turbo-supercharging; b – engines with a turbo-supercharging; 1 – the smoothing receiver; 2 – perepuskny electromagnetic valve; 3 – air consumption measuring instrument; 4 – the sensor of temperature of the soaked-up air; 5 – air valve; 6 – pneumatic shock-absorber; 7 – throttle knot; 8 – screw of adjustment of frequency of rotation of a bent shaft of the engine idling; 9 – sensor of an angle of opening of a butterfly valve; 10 – turbocompressor


Fig. 15.13. System of air supply of engines with a turbo-supercharging and an intermediate cooler: 1 – resonator; 2 – intermediate cooler; 3 – turbocompressor; 4 – inlet collector; 5 – camera of formation of a stream; 6 – throttle knot; 7 – valve of the bypass air canal; 8 – air consumption measuring instrument


The system of air supply consists of the air filter, the measuring instrument of a consumption of air and throttle knot. Automatic adjustment of frequency of rotation of a bent shaft idling depending on various operating conditions of the engine is provided by means of the auxiliary air valve integrated with the perepuskny electromagnetic valve (fig. 15.12, 15.13). The measuring instrument of a consumption of air transfers information on amount of the air which is soaked up by the engine to the control unit. The expense and air temperature on an entrance to a nozzle are measured by means of the compensator and the sensor of temperature. On the basis of these these measurements the control unit defines amount of injectable fuel or duration of injection. The provision of a butterfly valve is set by the driver. In process of opening of a butterfly valve the amount of the air passing through system increases, the compensator opens even more and the control unit develops a signal which operates a power supply system fuel, the portion of injectable fuel increases.

Electronic control system
The electronic control system operates system of electronic injection of fuel and other systems via the control unit containing the microprocessor, so-called EGI block.

Fig. 15.14. An arrangement of elements of an electronic control system of the engine without turbo-supercharging: 1 – three-running electromagnetic distributor; 2 – the operating pressure regulator valve; 3 – sensor of atmospheric pressure; 4 – three-running electromagnetic distributor; 5 – control unit; 6 – relay of the fuel pump; 7 – the sensor of temperature of the soaked-up air; 8 – control air valve; 9 – main relay; 10 – air consumption measuring instrument; 11 – temperature switch; 12 – analog sensor of temperature of cooling liquid; 13 – sensor of concentration of oxygen; 14 – air valve; 15 – thermostat; 16 – the control valve of recirculation of the fulfilled gases; 17 – pneumatic shock-absorber; 18 – the recirculation valve with the smooth characteristic;
19 – sensor of an angle of opening of a butterfly valve; 20 – perepuskny electromagnetic valve


On EGI block signals from a number of sensors which trace such parameters as volume of the soaked-up air, air temperature and cooling liquid, the frequency of rotation of a bent shaft, the mode of acceleration or braking, content of oxygen in the fulfilled gases arrive. On the basis of these data the microprocessor block counts the injection duration necessary for maintenance of an optimum ratio of fuel-air mix. Some sensors and the corresponding electromagnetic actuation mechanisms operated by the EGI block are located in a motor compartment and are not a part of the block (fig. 15.14, 15.15).

Fig. 15.15. An arrangement of elements of an electronic control system of the engine with a turbo-supercharging: 1 – саморазблокирующееся relay of the fuel pump; 2 – the operating pressure regulator valve; 3 – three-running electromagnetic distributor; 4 – control unit; 5 – the sensor of temperature of the soaked-up air; 6 – control air valve; 7 – main relay; 8 – air consumption measuring instrument; 9 – analog sensor of temperature of cooling liquid; 10 – temperature switch; 11 – sensor of concentration of oxygen; 12 – air valve; 13 – the control valve of recirculation of the fulfilled gases; 14 – the position sensor of recirculation of the fulfilled gases; 15 – case of the reed valve; 16 – pneumatic shock-absorber; 17 – throttle knot; 18 – electromagnetic valve of recirculation; 19 – perepuskny electromagnetic valve; 20 – pressure relay; 21 – sensor of atmospheric pressure


PREVENTIONS
The power supply system is under pressure. Before separation of elements of a power supply system it is necessary to take off pressure in system. For this purpose close the place of separation by pure rags and, being careful, smoothly unscrew a connecting nut.
Gasoline is extremely flammable, during the work with elements of a power supply system use of fire, the sparking devices opened by fire-dangerous devices of lighting, smoking is forbidden. It is necessary to avoid emergence of sparks during the work with wires and electric devices.

General diagnostics
Malfunctions of system of electronic injection of fuel, as a rule, do not become an engine cause of failure. Malfunction usually is caused by violation of connection of contacts in sockets and connectors of wires, and also fuel pollution that leads to a contamination of nozzles. Constantly check reliability of connections by easy percussion on sockets or their twitching – the signal should not vanish. Make sure that on all contacts of sockets there are no mechanical damages and both reciprocal parts of the socket are inserted each other against the stop and are recorded by latches. Before starting troubleshooting in system of electronic injection, surely check a condition of system of ignition. Make sure that the rechargeable battery, fusible inserts, safety locks, connections with "weight", the ignition coil, a high-voltage wire of the coil of ignition, the ignition distributor, high-voltage wires of spark plugs and spark plugs are in good repair and work without refusals. Check a corner of an advancing of ignition and frequency of rotation of a bent shaft of the engine idling. Check such indicators of a condition of the engine as a compression in cylinders and a gap in the mechanism of the drive of valves.
Check lack of a leak in a power supply system. Be convinced of serviceability of the fuel pump and check lack of pollution in the fuel filter. Check tightness of details of system of air supply. The detachment or damage of such elements as the index of level of engine oil, a cover of an oil-filling mouth, a hose of system of compulsory ventilation of a case can cause interruptions in operation of the engine. Check passing of air via the air filter.
Exhaustive diagnostics of system of electronic injection requires the special diagnostic unit, but some tests and checks can be executed also by means of the standard equipment which is available on sale.

Pressure decrease in a power supply system
Remove a stopper from a bulk mouth of the fuel tank therefore pressure in it will become equal atmospheric.
On models 1986 and 1987 of years of release for access to the socket of the fuel pump remove pillows of a back seat. On models since 1988 open a cowl and find the relay of the fuel pump (it is in a motor compartment near the coupling drive).
On models 1986 and 1987 of years of release launch the engine and disconnect the socket, on models since 1988 disconnect a wire from саморазблокирующегося the relay of the fuel pump. Leave the engine to work until the stop connected with lack of fuel in the distributive fuel highway.
Switch off ignition and disconnect a wire from the negative plug of the rechargeable battery.
As a result of the performed operations pressure in a power supply system fuel decreases. Close any connection of a power supply system fuel pure rags and, being careful, smoothly turn off a connecting nut.

Check of pressure in a power supply system
For check of pressure in a power supply system fuel the manometer and the corresponding adapter is necessary for connection to system.
Reduce pressure in a power supply system fuel. Again connect the socket of the fuel pump or connect a wire to the pump relay.
Remove the hose connecting the fuel filter to the fuel distributive highway and in a gap install the manometer, having screwed it on a tee.
Launch the engine and warm up it up to the working temperature. Check fuel pressure.
If pressure of fuel is absent (even at the working fuel pump), perhaps, the fuel filter which is consistently switched on in the highway is littered. Replace the filter and again check pressure. If pressure is still absent, the contamination of the fuel highway can be the cause. If the highway is not littered, check the filter on an entrance of the fuel pump. Check the electric resistance of the pump.
If fuel pressure low, can be the cause a partial contamination of the filter on an entrance of the fuel pump. Replace the filter and again check pressure. If pressure still low, check tightness of connection of the pipeline and all highway. Check tightness of the regulator of pressure, the fuel distributive highway and nozzles. If the leak is not revealed, press the fuel return pipeline (a hose in a junction with pressure regulator) and a crossing point connect diagnostic contacts of the socket on a partition of a motor compartment (fig. 15.16). Remember the indication of pressure. If pressure above the lower limit, so the fuel pressure regulator is faulty. If after replacement pressure still low, replace the fuel pump.
If fuel pressure high, disconnect a flexible hose of return of fuel and put on the released union from pressure regulator a rubber hose with an internal diameter about 8 mm. Place other end of a hose in a vessel with fuel. A crossing point connect diagnostic contacts of the socket on a partition of a motor compartment and remember the indication of pressure. If pressure is still higher than the lower limit, replace pressure regulator. If after replacement pressure meets standard, so the fuel return pipeline is littered.

Power supply system elements fuel

PREVENTIONS
The power supply system is under pressure. Before separation of elements of a power supply system it is necessary to take off pressure in system. For this purpose close the place of separation by pure rags and, being careful, smoothly unscrew a connecting nut.
Gasoline is extremely flammable, during the work with elements of a power supply system use of fire, the sparking devices opened by fire-dangerous devices of lighting, smoking is forbidden. It is necessary to avoid emergence of sparks during the work with wires and electric devices.


Fuel pump
Diagnostics of the fuel pump and check of pressure see above in the subsection "Check of Pressure in a Power Supply System".
For check of resistance of the fuel pump remove a back seat and disconnect the pump socket.

Fig. 15.17. Use of an ohmmeter for measurement of resistance of the fuel pump: And, In – contacts


Measure resistance between contacts "And" and "In" the socket (fig. 15.17). Resistance has to be about 0,3 Ohms.
For replacement of the fuel pump reduce pressure in a power supply system fuel, then disconnect a wire from the negative plug of the rechargeable battery.
Remove a service cap and push out a rubber sealant and wires from an opening.

PREVENTION
It is forbidden to carry out the operations given below at the filled fuel tank. Merge fuel in the capacity intended for it, using the pump (it is forbidden to merge gasoline suction in a hose).

Adhesive tape mark pipelines of giving and return of fuel. Weaken collars of fastening of hoses and disconnect hoses.
Turn off bolts of fastening of an arm of the pump and take out the pump and an arm from the fuel tank.
Disconnect wires from pump conclusions.

Fig. 15.18. Elements of fastening of the fuel pump: 1 – the filter (it is located in a tank); 2 – pump; 3 – pump hose; 4 – arm


Weaken the screw of a collar of fastening of a hose of the pump, move a collar to the middle of a hose, then remove the pump from an arm. Take the pump from an arm bracket (fig. 15.18).
Remove a rubber pillow and the filter from the lower part of the pump, having hooked and having removed for this purpose a lock ring.
Installation is carried out to the sequences, the return to removal. Replace laying between a tank and an arm of the pump.
The operating pressure regulator valve
The operating valve of the regulator of pressure is installed on a wall of a motor compartment, between two three-running electromagnetic distributors. It is the electromagnetic valve activated by the control unit. The valve, in turn, operates the fuel pressure regulator according to the changing depression.

Fig. 15.19. Check of operating pressure regulator valve: 1 – contact for giving of tension from the rechargeable battery; 2 – hose; 3 – air filter; 4 – lower union of the valve


For valve check put on a hose the top union (fig. 15.19). Blow in a hose and be convinced that air goes out of the lower union. Connect "weighing" one of filter conclusions, and on another give tension from the battery. Blow in a hose and be convinced that air still goes out of the lower union of the filter. If result of both tests negative, replace the filter.
For removal of the filter disconnect wires and hoses, previously having marked their arrangement. Take the valve from an arm, having pulled for a plastic latch. Installation is carried out to the sequences, the return to removal.
Fuel pressure regulator
Check fuel pressure.
Reduce pressure in a power supply system fuel then disconnect a wire from the negative plug of the rechargeable battery.
Weaken a collar of fastening of a hose of the pipeline of return of fuel and disconnect a hose from pressure regulator, previously having enclosed rags for collecting the spilled fuel.
Remove a depression control hose from the regulator.
Turn off two bolts of fastening of the regulator and remove the regulator from the fuel distributive highway.
Install pressure regulator with new laying to the fuel distributive highway and fix by bolts.
Attach a hose of return of fuel and a hose for depression control.
Connect a wire to the negative plug of the rechargeable battery and turn a key in the ignition switch in the provision of "ON". Fill system up to the working pressure for what connect a crossing point diagnostic contacts of the socket of the fuel pump. Check lack of leak of fuel.
Damper
The damper is established in an end face of the fuel distributive highway and intended for smoothing of sharp pulsations of pressure of fuel which arise when closing and opening nozzles.

Fig. 15.20. An arrangement of a damper (1) in an end face of the fuel distributive highway


For check of a damper apply a finger to an opening at an end face – during the operation of the engine pulsations have to be felt (fig. 15.20). If pulsations are absent, replace a damper.
For replacement of a damper reduce pressure in a power supply system, then disconnect a wire from the negative plug of the rechargeable battery.
Disconnect the pipeline and turn out a damper from the fuel distributive highway.
Installation is carried out to the sequences, the return to removal.
Fuel distributive highway
Reduce pressure in a power supply system, then disconnect a wire from the negative plug of the rechargeable battery.
Disconnect the pipeline of return of fuel from the regulator of pressure and the pipeline from a damper.
Disconnect sockets from nozzles.
Turn out two bolts and carefully disconnect the fuel distributive highway with nozzles from an inlet collector. Take all knot assembled, having stretched it under throttle knot and the smoothing receiver.
Installation is carried out to the sequences, the return to removal. Surely examine rubber laying between a nozzle and an inlet collector and at detection of cracks, hardening or deformations replace them.
Nozzles
For bystry check put an edge of the long screw-driver in turn to the case of each of nozzles and listen to click from needle valves. If clicks are not heard, check resistance of nozzles.
Remove the fuel distributive highway.
For check of tightness of nozzles connect a hose from the fuel filter to the inlet union on the fuel distributive highway. By means of an additional piece of a fuel hose and an adapter connect a hose of the pipeline of return of fuel to the fuel pressure regulator.
Tie nozzles to the fuel distributive highway, it will prevent their loss at increase in pressure of fuel.

Fig. 15.16. Connection by a crossing point (1) of contacts of the diagnostic socket for launch of the fuel pump


Spread rags under nozzles. Turn a key in the ignition switch in the provision of "ON" and, having connected a crossing point contacts of the control socket of the fuel pump, launch the pump (see fig. 15.16). You monitor emergence of drops or traces of infiltration of fuel from nozzles. Replace a nozzle with leak of fuel.

PREVENTION
Emergence of a small amount of gasoline in 5 min. is allowed.

By means of an ohmmeter be convinced that resistance between two contacts of each of nozzles equally in 12-16 Ohms. Otherwise the nozzle is faulty, it needs to be replaced.
For replacement of a nozzle disconnect an auxiliary hose which was used when checking tightness. To prevent emission of fuel from a hose, wind it with rags as it is impossible to reduce fuel pressure in system at the removed fuel distributive highway.
Remove rubber sealing rings and plugs, nozzles and insulators.
It is recommended to replace periodically these elements for an exception of possible leak of fuel.
Establish new rubber sealing rings, plugs and insulators.

Fig. 14.20. Arrangement of consolidations of a nozzle: 1 – sealing ring; 2 – fuel distributive highway; 3 – sealing plug; 4 – inlet collector; 5 – insulator


For simplification of installation and decrease in probability of damages grease a ring and the insulator with a thin layer of engine oil (see fig. 14.20).
Insert a nozzle into the fuel distributive highway, at the same time the socket has to be directed up. It is necessary to insert a nozzle strictly along its axis, otherwise it is possible to damage a sealing ring.
Establish the fuel distributive highway with nozzles and fix by bolts. Attach hoses of giving and return of fuel and a depression control hose. Restore pressure in a power supply system, having connected a crossing point contacts of the control socket of the fuel pump, and check tightness of system.
Relay of the fuel pump

Fig. 15.21. Arrangement of the relay (1) of the fuel pump


The relay of the fuel pump is installed on panels under the pneumatic shock-absorber. It is intended for power supply of the fuel pump during launch of the engine by a starter (fig. 15.21). Food moves to the pump to
switching off of a starter, at this moment there is an automatic unblocking of the relay (when the key passes the provision of "ON" in the switch of ignition, food on the pump does not move as first of all the engine has to be launched).

Fig. 15.22. Arrangement of contacts of the socket of the self-locking relay: Fp – to the fuel pump; Fc – to the switch of the fuel pump;
In – to the switch of ignition ("ON")


For check of the relay and wires open a measuring plate in the air consumption measuring instrument, block it and measure tension on each contact of the socket of the relay, without disconnecting the relay from the socket (fig. 15.22). If tension on contact "In" differs from provided in tab. 15.1, check safety locks and wires from the ignition switch.

Table 15.1
Tension on contacts of the socket of the self-locking relay


Fig. 15.23. Arrangement of contacts of the self-locking relay


If tension deviation on contact of "STA" is revealed, check wires from the ignition switch. At the incorrect indication on contact of "E1" check connection with "weight". If tension deviation on contact of "FC" is revealed, check resistance of the measuring instrument of an expense or winding of the relay (fig. 15.23). Values of resistance on contacts of the relay are given in tab. 15.2.

Table 15.2
Resistance between contacts of the self-locking relay

If the indication on contact of "FP" differs, check resistance of the self-locking relay.
For replacement of the relay disconnect the socket and turn out the fastening screw. Installation is carried out to the sequences, the return to removal.

Elements of system of air supply
Turn out two screws and pull together a rubber cover from the air consumption measuring instrument socket.

Fig. 15.24. An arrangement of contacts on the air consumption measuring instrument socket


Turn a key in the ignition switch in the provision of "ON" and measure tension between each contact of the socket and "weight" (fig. 15.24). Compare indications with provided in tab. 15.3.

Table 15.3
Tension on contacts of the socket of the measuring instrument of a consumption of air

If there is a deviation from rated voltage, check the main safety lock, the main relay of the measuring instrument and a wire.

Fig. 15.25. Use of the screw-driver for release of a bracket of fixing of the socket of the measuring instrument of a consumption of air


For a socket detachment exempt a spring bracket from the measuring instrument of a consumption of air, having hooked it the small screw-driver (fig. 15.25).
Measure resistance between contacts of the socket (see fig. 15.24). Values of resistance are given in tab. 15.4.

Table 15.4
Resistance between contacts of the socket of the measuring instrument of a consumption of air in a starting position of a plate of the measuring instrument

Sharply (push) open a measuring plate and measure resistance between contacts according to tab. 15.5.

Table 15.5
Resistance between contacts of the socket of the measuring instrument of a consumption of air after a measuring instrument plate deviation

At resistance deviation from nominal replace the air consumption measuring instrument.
For replacement of the measuring instrument of a consumption of air weaken a collar and remove a hose from the top cover of the air filter. Disconnect the socket and remove a vacuum hose from the control air valve.

Fig. 15.26. Elements of fastening of the measuring instrument of a consumption of air: 1 – rubber ring; 2 – cover assembled; 3 – air consumption measuring instrument


Separate the top cover of the air filter from the basis and take out the measuring instrument from the top cover (fig. 15.26).
Installation is carried out to the sequences, the return to removal. Surely establish a rubber ring between the measuring instrument and the top cover.

PREVENTION
Position of the adjusting screw of a butterfly valve is established by the manufacturer, adjustment in use of the car is not allowed.

Throttle knot
Check smoothness of movement of draft of a butterfly valve. Jamming can be caused by resinous deposits from a reverse side of the gate which get from system of ventilation of a case through a hose to the smoothing receiver and an inlet collector. To remove deposits, it is necessary to remove the pipeline of a butterfly valve, to open a butterfly valve and to clean carefully a small emery paper. At the same time do not damage a thin covering of the gate and a wall of the case.

Fig. 15.27. An arrangement of unions of throttle knot of the engine without turbo-supercharging


Fig. 15.28. An arrangement of unions of throttle knot of the engine with a turbo-supercharging


Warm up the engine up to the working temperature, check depression on each union of throttle knot (fig. 15.27, 15.28) and compare results to the data provided in tab. 15.6, 15.7.

Table 15.6
Depression on unions of throttle knot of the engine without turbo-supercharging

Table 15.7
Depression on unions of throttle knot of the engine with a turbo-supercharging

If results differ from demanded, clean or blow channels compressed air.
If it is necessary to remove throttle knot, first of all disconnect a wire from the negative plug of the rechargeable battery.
Remove the air duct established between throttle knot and the measuring instrument of a consumption of air.
Disconnect a returnable spring of a butterfly valve.
Disconnect a cable of control of the gate from the lever.

Fig. 15.29. Standard elements of fastening of throttle knot: 1 – vacuum hose; 2 – perepuskny air hose; 3 – hose of cooling liquid; 4 – throttle knot; 5 – laying; 6 – vacuum hose


Disconnect vacuum hoses in the top part of throttle knot (fig. 15.29).
Disconnect the socket from the sensor of an angle of opening of a butterfly valve.
Merge about 1,0 l of cooling liquid from a radiator. Disconnect from throttle knot a hose of cooling liquid and perepuskny an air hose.
Turn off four nuts and remove throttle knot.
Edge of the razor clear the remains of laying from the broad camera and throttle knot, otherwise after installation of throttle knot the air suction is possible.
Remove from throttle knot the remains of resinous deposits and dirt, washout in pure solvent or a cleaner of a deposit. Especially carefully wash out places near a butterfly valve.

PREVENTION
Immersion of the sensor of an angle of opening of a butterfly valve in any solvent or a cleaner is not allowed. Otherwise damage of plastic walls and located in the electronic scheme is possible.

At an opportunity blow compressed air vacuum channels.
Installation is carried out to the sequences, the return to removal.

Check of the air valve

Fig. 15.30. Use of pincers for a perezhatiya of a perepuskny air hose


Launch the engine and leave it to idle. In the course of warming up of the engine pincers press perepuskny an air hose, the frequency of rotation of a bent shaft of the engine has to decrease a little (fig. 15.30). If it does not occur, check tightness of the air valve and a vacuum hose.
Warm up the engine up to the working temperature. Again press a hose, the frequency of rotation of a bent shaft of the engine has to decrease for 100–200 min.-1. If reduction of frequency exceeds 200 min.-1, check presence of tension on contacts of the socket of the air valve.
For check of tension on contacts of the socket of the air valve disconnect the socket and check tension given from the battery. If low voltage or is absent, check wires or the relay of the fuel pump.
Check resistance of the air valve which has to be 30–45 Ohms. If resistance does not meet standard, replace the air valve.
For check of operability of the air valve remove one of hoses, attach a piece of a hose and blow the valve, at the same time the key in the switch of ignition has to be in the provision of "ON".
At a temperature of valve not above 20 °C air has to pass through the valve freely. At a temperature above 20 °C the valve has to be closed.
For replacement of the valve weaken collars and remove hoses. Disconnect the socket, unscrew screws and remove the valve.
Installation is carried out to the sequences, the return to removal.

Pneumatic shock-absorber
For check of the pneumatic shock-absorber a finger press a rod – it has to utaplivatsya slowly with a noticeable resistance to effort of pressing. At an otpuskaniye the rod has to return to a starting position quickly.

Fig. 15.31. Movement of a rod of the pneumatic shock-absorber before contact with the lever of a butterfly valve with a frequency of rotation of 1900-2500 min.-1: 1 – rod; 2 – lever of a butterfly valve; 3 – lock-nut


Connect a tachometer to the engine and finish the frequency of rotation of a bent shaft of the engine up to 2500 min.-1. Slowly reduce the frequency of rotation and define with what frequency of rotation the rod of the pneumatic shock-absorber will concern the lever of a butterfly valve (fig. 15.31). The rod has to concern the lever with a frequency of rotation of 1900-2500 min.-1. If it does not occur, release a lock-nut and, rotating the pneumatic shock-absorber, adjust its situation. For replacement turn off a lock-nut and turn out the pneumatic shock-absorber from an arm.

System of compensation of frequency of idling (model of release of 1986 and 1987)

Fig. 15.32. Scheme of system of compensation of frequency of idling (models 1986 and 1987 of years of release): 1 – sensor of atmospheric pressure; 2 – the sensor of temperature of the soaked-up air; 3 – sensor of temperature of cooling liquid; 4 – ignition switch; 5 – conditioner switch; 6 – conditioner relay


The system of compensation of frequency of idling is intended for automatic increase in frequency of rotation of a bent shaft which decreases under the influence of additional loading from the drive of the conditioner and/or the hydraulic booster of steering at small speeds of the movement of the car, at operation in the mountain area or in the conditions of hot climate. Frequency of idling increases due to increase in air flow in an inlet collector via the perepuskny electromagnetic valves activated by the control unit and also from switches of the conditioner and the hydraulic booster of steering. Besides, on the control unit signals from the sensor of atmospheric pressure, the sensor of temperature of cooling liquid and the sensor of temperature of the air which is soaked up by the engine also arrive. On the basis of these data the control unit gives the command to open the specified valves (fig. 15.32).
Before adjustment of perepuskny valves it is necessary to determine the frequency of rotation of a bent shaft idling and if necessary to adjust.

Fig. 15.33. Arrangement of contacts of the socket of perepuskny valves of system of compensation of frequency of idling


Connect a tachometer. At the disconnected socket of perepuskny valves give on contact of "VAT" voltage of 12 V from the rechargeable battery, connect contact of "GRD" to "weight" (fig. 15.33). Check contacts in pairs. Compare the received rotation frequency to the values given in tab. 15.8.

Table 15.8
Frequency of rotation of a bent shaft of the engine when giving tension on contacts of "VAT" and "GRD"

Check the frequency of rotation of a bent shaft idling for all valves. If rotation frequency idling differs from demanded, rotation of screws adjust valves.
Measure resistance of each valve. If resistance of any valve differs from the values given in tab. 15.9, replace the valve.

Table 15.9
Resistance of perepuskny valves of system of compensation of frequency of idling of models 1986 and 1987 of years of release


Fig. 15.34. Use of the voltmeter for check of signals of compensation of frequency of rotation in the idling mode on the electromagnetic valve of compensation of loading at turning on of the conditioner or amplifier of steering


For check of a signal of turning on of the conditioner operating the perepuskny valve warm up the engine up to the working temperature and between contact "And" (in the socket of the perepuskny electromagnetic valve) and "weight" turn on the voltmeter (fig. 15.34). Turn on the conditioner and the fan, check the indication of the voltmeter which has to be equal to tension of the rechargeable battery. If the indication differs, check the relay and the switch of the conditioner, the conditioner electric motor switch, safety locks and wires.
For check of a signal of turning on of the amplifier of the steering operating the perepuskny valve connect the voltmeter between contact of "D" and "weight". Ask the assistant to turn a steering wheel against the stop to the left and to the right; you monitor indications of the voltmeter which have to be equal to zero.
If indications differ, check the switch of the amplifier of steering and a wire.
For check of the operating compensation signal in mountain conditions warm up the engine and leave it to work in the idling mode. Connect the vacuum pump to the entrance union of the sensor of atmospheric pressure, and "In" and "F" connect the voltmeter to contacts. During depression creation the voltmeter has to show zero. At depression removal the indication has to be equal to tension of the rechargeable battery. If indications differ, check the sensor of atmospheric pressure and a wire.
For check of the operating compensation signal in the conditions of hot climate warm up the engine and leave it to work in the idling mode. Turn on the voltmeter between contact of "TNA" of the sensor of temperature of the soaked-up air (it is installed in the air consumption measuring instrument socket) and "weight". Heat the hair dryer the sensor to temperature of 55 °C – the indication of the voltmeter has to be equal to zero. If indications differ, check the sensor of temperature of the soaked-up air.

Check, removal and installation of elements of an electronic control system
The sensor of temperature  of the air of models 1986 and 1987 of years of release which is soaked up in the engine
Uncover the air filter. Measure by the ohmmeter connected to contacts of "E2" and "TNA" of the socket of the measuring instrument of a consumption of air resistance of the sensor of temperature of the air which is soaked up in the engine at various values of temperature and compare to the data provided in tab. 15.10 (see fig. 15.24).

Table 15.10
Dependence of resistance of the sensor of temperature of the air which is soaked up in the engine on temperature

For heating of the sensor use the hair dryer, for cooling – artificial ice, having densely laid it around the sensor. If resistance differs from demanded, replace the air consumption measuring instrument.
Sensor of temperature of cooling liquid
Measure tension on contacts of the socket of the sensor. For this purpose remove a rubber cover from the socket, turn a key in the ignition switch in situation "ON" and measure by the voltmeter tension which has to be about 0,05 Century. If tension differs, measure resistance of the sensor and check wires.
For check of resistance remove the sensor from the engine. Lower the sensor in the glass vessel filled with water and, heating water to boiling, measure resistance at various values of temperature. For measurement of resistance at a low temperature densely impose the sensor with artificial ice. Resistance of the sensor of temperature of cooling liquid depending on temperature is specified in tab. 15.11.

Table 15.11
Dependence of resistance of the sensor of temperature of cooling liquid on temperature

If resistance differs from the values given in tab. 15.11, replace the sensor.
Before removal of the sensor cool the engine and merge cooling liquid up to one level lower than the sensor. Disconnect the socket and turn out the sensor from the engine. Before installation wrap up a sensor carving a teflon tape.
Sensor of atmospheric pressure

Fig. 15.35. Arrangement of contacts of the sensor of atmospheric pressure


Remove a cap from the sensor and attach the vacuum pump. Turn a key in the ignition switch in the provision of "ON". Measure tension on each contact during creation of depression and without it (fig. 15.35). Tension on contacts of the sensor depending on depression see in tab. 15.12.

Table 15.12
Tension on contacts of the sensor of atmospheric pressure depending on depression

If tension on contacts "And", "With" or "D" differs from provided in the table, check wires. If tension on contacts "And", "With" or "D" corresponds provided in the table, and on contact "In" differs, replace the sensor.
For replacement of the sensor disconnect the socket, turn out two bolts and remove the sensor. Installation is carried out to the sequences, the return to removal.
Thermal sensor
Cool the engine and merge cooling liquid up to one level lower than the thermal sensor. Disconnect the socket, turn out the sensor from a radiator and measure its resistance. At a temperature more than 13-19 °C the ohmmeter has to show short circuit, otherwise replace the thermal sensor.
Sensor of an angle of rotation of a butterfly valve

Fig. 15.36. Arrangement of contacts of the socket of the sensor of an angle of rotation of a butterfly valve


Remove a rubber cover from the sensor socket, turn a key in the ignition switch in the provision of "ON". Measure tension between contacts of the sensor and "weight" and write down values (fig. 15.36). Completely open a butterfly valve and again measure tension. Compare results of measurements to the data provided in tab. 15.13.

Table 15.13
Tension on contacts of the socket of the sensor of an angle of rotation of a butterfly valve depending on a condition of contacts

If from provided in tab. 15.13 only tension on contact of "D" differs, check position of the sensor. If values on other contacts differ, measure resistance between contacts of the sensor.

Fig. 15.37. Installation of the probe between the lever of a butterfly valve and the adjusting screw when checking resistance between contacts "In" and "D"


For verification of the provision of the sensor on models 1986 and 1987 of years of release insert between the lever of a butterfly valve and the adjusting screw the probe 0,4 mm thick (fig. 15.37) and check existence of connection of contacts "In" and "D". Insert the probe 0,55 mm thick, the ohmmeter has to show infinity. If values differ, adjust the sensor, rotating it until it does not reach the correct position.
Disconnect the socket from the sensor of an angle of rotation of a butterfly valve and measure resistance between contacts "And" and "In", "In" and "With" (see fig. 15.36). If values of resistance differ from provided in tab. 15.14, replace the sensor.

Table 15.14
Resistance between contacts of the socket of the sensor of an angle of rotation of a butterfly valve depending on a condition of contacts

For replacement of the sensor of an angle of opening of a butterfly valve disconnect the socket and turn out two screws. At installation of the sensor combine the gate blade with a groove on the sensor, screw the sensor into place and fix by two screws. Adjust position of the sensor.
Sensor of concentration of oxygen
For check of the sensor of concentration of oxygen launch the engine and warm up up to the working temperature. Disconnect the socket and connect the voltmeter to a part of the socket from the sensor. Increase the frequency of rotation of a bent shaft of the engine up to 4000 min.-1 – the voltmeter has to show 0,55 Century. Several times press and release an accelerator pedal, reading out indications. At increase in frequency of rotation of the indication of the voltmeter have to be in limits 0,5-1,0 B, at reduction of frequency of rotation – 0–0,4 Century. If tension differs, replace the sensor of concentration of oxygen.
For replacement of the sensor disconnect the socket and turn out the sensor from a final collector.
Before installation replace a sealing washer and grease a carving with the structure preventing its burning. Reliably tighten the sensor.
Pressure sensor in an inlet collector (only for engines with a turbo-supercharging of early releases)
Disconnect a hose from the sensor. Create on the sensor air pressure about 0,6 atm.

PREVENTION
Pressure should not exceed 0,85 atm. Otherwise the valve will fail.


Fig. 15.38. Check of tension on contacts of the socket of the sensor of pressure in an inlet collector when giving pressure of 0,6 atm


Measure tension on a wire of brown-white color of the socket of the sensor (fig. 15.38). At influence of pressure the indication should not exceed 1,5 B, and at removal of pressure – there have to be about 12 Century. If indications differ, check wires and resistance of the sensor.
For check of resistance disconnect the socket and connect an ohmmeter to contacts of the sensor. Create on the sensor air pressure about 0,6 atm and consider the indication. The ohmmeter has to show the closed chain, otherwise replace the sensor.
Switch of the amplifier of steering

Fig. 15.39. Measurement of resistance between contacts of the socket of the switch of the amplifier of steering


For check of the switch of the amplifier of steering launch the engine and set the idling mode. Disconnect the socket from the switch and connect an ohmmeter to contacts of the switch (fig. 15.39). Ask the assistant to turn a steering wheel against the stop to the right or to the left, at the same time the ohmmeter has to show the closed chain. At any intermediate position of a steering wheel the ohmmeter has to show infinity. If result of both tests negative, replace the switch.
Install the new switch on completely cooled down engine. At the idle engine turn a steering wheel in both parties for removal of residual pressure in the amplifier of steering. Disconnect the socket and turn out the switch. By hand screw the new switch, previously having wrapped up it a teflon tape, then tighten a key. Connect the socket and check oil level in the amplifier of steering.
Switch of stoplights
Disconnect the socket from the switch of stoplights located under the dashboard. Connect an ohmmeter to contacts of the socket of the switch and measure resistance at the pressed brake pedal – resistance has to be equal to zero. Release a pedal – resistance has to equal infinity. If results of both tests negative, adjust position of the switch, turning out or rolling it.

Fig. 15.40. Arrangement of a lock-nut (1) of fastening of the switch of stoplights


For replacement of the switch disconnect the socket, turn off a lock-nut from a rod of the switch and take the switch from an arm (fig. 15.40). Installation is carried out to the sequences, the return to removal. After installation adjust position of the switch.
Coupling switching off sensor
Disconnect the socket from the sensor of switching off of coupling and connect an ohmmeter to contacts of the socket of the sensor. At the released coupling pedal resistance has to be equal to zero, and at pressed – infinity. If indications differ, adjust position of the sensor (similar to adjustment of the switch of stoplights).
Sensor of neutral position of the mechanical transmission

Fig. 15.41. Arrangement of the sensor of neutral position of the mechanical transmission


Disconnect the socket from the sensor of neutral situation which will be screwed in a transmission case (fig. 15.41). Connect an ohmmeter to contacts of the sensor and measure resistance. At installation of the lever of gear shifting in neutral situation resistance has to be equal to infinity. At inclusion of any transfer the ohmmeter has to show zero. If indications differ, replace the sensor. For prevention of leak of oil wrap up at installation a sensor carving a teflon tape.
The sensor of delay of models with the automatic transmission

Fig. 15.42. An arrangement of contacts "And" and "In" the sensor socket (model with the automatic transmission)


The sensor of delay is screwed in a case of the automatic transmission. Disconnect the sensor socket located on a wire, and connect an ohmmeter to contacts "And" and "In" from the sensor (fig. 15.42). At installation of the lever of the selector in provisions "parking" or "neutral" the ohmmeter has to show zero, and at any other position of the selector resistance has to be equal to infinity. If indications differ, replace the sensor.
Sensor of inclusion of the 5th transfer

Fig. 15.43. Arrangement of contacts of the socket (1) of the sensor of inclusion of the 5th transfer


The sensor is screwed in a transmission case. Disconnect the socket and connect an ohmmeter to contacts of the socket located on a wire from the sensor (fig. 15.43). At inclusion of the 5th transfer the ohmmeter has to show infinity, and at inclusion of any other transfer or resistance has to be equal in neutral position of the transmission to zero. If indications differ, replace the sensor.
For replacement of the sensor of the 5th transfer lift the car and fix on supports. Under the transmission install the pallet and turn out the sensor from a case. Screw by hand the new sensor, previously having wrapped up its carving a teflon tape, and reliably tighten a key. Restore oil level in the transmission.

Main relay
Model 1986-1987 of years of release

Fig. 15.44. Voltage measurement on contacts of the main relay of models 1986-1987 of years of release


Measure tension on each contact of the main relay (fig. 15.44). On contacts "And", "With" and the "D" tension has to be 12 V, on contact "In" – zero. If values of tension differ, measure relay resistance.
Remove the relay from the car and measure resistance between contacts "And" and "In" which to be about 70 Ohms. Then give tension from the battery on contact "And" and connect to "weight" contact "In", at the same time watching resistance between contacts "With" and "D" which has to be equal to zero. At negative results of both tests replace the relay.
Model 1988-1991 of years of release
Make sure that at turn of a key in the ignition switch in provisions of "ON" and "OFF" the main relay publishes characteristic click.

Fig. 15.45. Measurement of resistance between contacts of the main relay of models 1988-1991 of years of release


Make sure that resistance between contacts of the relay "C" and "D" at power supply of the relay from the battery has to be equal to zero, and at power off between these contacts it has to be equal to infinity (fig. 15.45).

Control unit
Diagnosing and service of the control unit have to be carried out by skilled experts with use of the special equipment therefore address to service of car service or in a specialized workshop.