798646e1

2.1. Failure diagnostics at start of the engine in road conditions

Check of systems of ignition and electric equipment

 PERFORMANCE ORDER

  1. Include ignition and make sure of serviceability of a luminescence of a control lamp on the dashboard.
  2. Include a starter and check stability of a provorachivaniye it the engine.
  3. Include head headlights and check intensity of their luminescence.
  4. If head headlights do not burn, or the starter does not turn the engine act as follows:
  1. Disconnect wires from the battery and smooth out both plugs and terminal clips (see an accompanying illustration). Again connect wires and reliably (but it is not excessive) tighten clips.

At bad contact of the plug usually are considerably warmed after several attempts of start.

    1. Check a state and reliability of fastening of tires of grounding of the battery for the engine, the engine on a frame. Also check contacts of tires for existence of signs of oxidation and pollution.
    2. Check serviceability of the wire going from the battery to a starter and also an external condition of the traction relay of a starter. Check also purity and reliability of fastening of plugs of a wire.
    3. Repeat verifications of the first three paragraphs of subsection. if the starter still does not turn the engine or lamps do not burn, one of the listed below situations is possible.

The starter or lamps does not function

Headlights burn, but the starter does not function

The drive of a starter is jammed, being entered into gearing with a gear wreath of a flywheel

Headlights shine with the lowered intensity, and the starter rotates too slowly

Models with the contact breaker

 PERFORMANCE ORDER

  1. Expose an interelectrode gap of a spare spark plug of the served type of equal 6 mm. Reliably ground the candle case by means of a wire crossing point (see an accompanying illustration), or having densely pressed a candle to reliably grounded point on the engine block (a primotayta its cord or an adhesive tape). Remove a candle wire and connect it to this trial candle.
  1. Ask the assistant to include a starter.
  2. Between electrodes of a trial candle the spark has to slip. If there is no spark, or it has yellow coloring and weak intensity, pass to implementation of the procedure of the following paragraph. If the spark has sufficient intensity, miss the checks described below.
  3. Disconnect an ignition coil wire from a cover of the distributor and bring it to a trial candle. Repeat the check described above. If on a candle the strong spark of brightly blue color is formed, the cause of failure lies in malfunction of a cover of the distributor, its runner, screen of switching of the limiter of turns or a candle wire. If the spark is still absent, switch off ignition and execute the following checks:
  1. Check a condition of VV of candle wires (see an accompanying illustration), - they have to be dry and without cracks in isolation.
  1. Check a distributor cover for availability of moisture and dirt. Examine internal surfaces of a cover and the screen of the limiter of turns of the distributor on existence of cracks and coal paths (see an accompanying illustration), paying special attention to sites between contact segments of spark plugs in a cover and electrodes in the screen.
  1. Check the distributor runner for existence of cracks, mud deposits and progar of a metal nose. Make sure of presence on the place and serviceability of a spring of restriction of rotation of the button of the runner (on an accompanying illustration check of a spring of the runner on model of 4.2 l is shown).
    1. Check purity, dryness and reliability of fastening in a cover of the distributor of contact connections of wires sechy and coils of ignition.
    2. Make sure that the coal brush in the center of an internal surface of a cover of the distributor is dry and pure.
    3. Check a state and reliability of fastening of NV of wires on the ignition coil. Make sure of lack of signs of oxidation of their plugs.
  1. Make sure that electric current reaches the coil at inclusion of ignition. Use a lamp sampler, having included it between NV the positive plug of the coil and well grounded point (see an accompanying illustration). Make sure that contacts of the breaker are opened, or insulate them for the period of carrying out by the dielectric tape given checks. If the lamp sampler lights up, being connected with the party of the coil turned to the lock of ignition and does not burn at connection to the party turned to the breaker of contacts, then the probability of damage of primary winding of the coil is not excluded. Remove the coil or check it by replacement by obviously serviceable.
    1. Check a condition of contacts of the breaker, in case of need smooth out them and adjust.
    2. Check a state and reliability of fastening of wires of grounding of the distributor.
      Repeat check. If the spark is still absent, or the weak spark of yellow color takes place, the probability of one of the listed below refusals is not excluded.

The lamp does not burn

The break of a chain between the lock of ignition and the positive plug of the coil takes place. Besides by means of a lamp sampler make sure of serviceability of giving of food on the lock of ignition and NV the engine electrical wiring plait socket.

If the lamp sampler available is absent, NV a wire can be disconnected from the party of the coil turned to the lock of ignition and to bring to reliably grounded point for the purpose of verification of current. Similar to the second NV the wire can be disconnected from the distributor and is grounded for verification of current. During performance of verification of point g) you watch that contacts of the breaker were opened (are insulated), and ignition is included (a key - in position of ON).

The coil, the condenser or candle wires is faulty

Points to failure of the coil strong прогар either contacts of the breaker or existence of deep cavities - replace the condenser and contacts of the breaker with them.

If during performance of the listed above checks and correction of the revealed defects it is possible to achieve a spark of sufficient efficiency, but the engine is still not started, remove all spark plugs and check their condition and size of interelectrode gaps.

Models with electronic ignition

 PERFORMANCE ORDER

  1. Expose an interelectrode gap of a spare spark plug of the served type of equal 6 mm. Reliably ground the candle case by means of a wire crossing point, or having densely pressed a candle to reliably grounded point on the engine block (a primotayta its cord or an adhesive tape). Remove a candle wire and connect it to this trial candle.

Working with electronic system of ignition or near its components it is necessary to observe the certain precautionary measures connected with danger of receiving electric shock at contact with the VV elements of primary and secondary contours of system.
Before starting a detachment or connection of any components of electronic system, switch off ignition in order to avoid receiving electric blow and failure of system of ignition.

  1. Ask the assistant to include a starter.
  2. Between electrodes of a trial candle the spark has to slip. If there is no spark, or it has yellow coloring and weak intensity, pass to implementation of the procedure of the following paragraph. If the spark has sufficient intensity, miss the checks described below.
  3. Disconnect an ignition coil wire from a cover of the distributor and bring it to a trial candle. Repeat the check described above. If on a candle the strong spark of brightly blue color is formed, the cause of failure lies in malfunction of a cover of the distributor, its runner, screen of the limiter of turns or a candle wire. If the spark is still absent, switch off ignition and execute the following checks:
    1. Check a condition of VV of candle wires - they have to be dry and without cracks in isolation.
  1. Check a distributor cover for availability of moisture and dirt. Examine internal surfaces of a cover and the screen of the limiter of turns of the distributor on existence of cracks and coal paths (see an accompanying illustration), paying special attention to sites between contact segments of spark plugs in a cover and electrodes in the screen of the limiter of turns.
    1. Check the distributor runner for existence of cracks, mud deposits and progar of a metal nose. Make sure of presence on the place and serviceability of a spring of restriction of rotation of the button of the runner (on an accompanying illustration check of a spring of a rotor on model of 4.2 l is shown).
    2. Check purity, dryness and reliability of fastening in a cover of the distributor of contact connections of wires sechy and coils of ignition.
    3. Make sure that the coal brush in the center of an internal surface of a cover of the distributor is dry and pure.

It is not necessary to make further checks of electronic system of ignition as their performance is connected with risk of receiving electric shock as a result of influence of the high voltage which is present at primary and secondary contours of system. Rules of performing procedures are described in the Section devoted to electronic system of ignition.

  1. If during performance of the listed above checks and correction of the revealed defects it is possible to achieve a spark of sufficient efficiency, but the engine is still not started, remove all spark plugs and check their condition and size of interelectrode gaps.

Check of a power supply system

On condition of a guarantee of availability of fuel in a gasoline tank check of presence of fuel at the float-operated camera of the carburetor has to become the first check. On the carburetors equipped with an observation port check presence of fuel at the camera visually. Level of fuel has to reach the middle of an observation port.

For performance of the following check remove assembly of the air cleaner and glance in a carburetor mouth at the open air gate. Continuing to look in a mouth, several times open and close a butterfly valve, moving a hand its draft. If at the movement of a butterfly valve injection of fuel through a digit nozzle of the accelerating pump is observed, it means that the float-operated camera is filled and the power supply system functions regularly (see an accompanying illustration).

If injection does not happen, act as it is described below.

 PERFORMANCE ORDER

  1. Disunite NV the ignition coil socket in order to avoid casual start of the engine during check performance.
  1. Disconnect a hose of supply of fuel from the carburetor and lower it in drain capacity. Ask the assistant to include several times a starter and watch pushing out of fuel from a hose. If fuel is splashed out in capacity regularly, miss the procedures described in three subsequent paragraphs if is not present - you pass to implementation of these procedures.
  1. Disconnect hoses and take the fuel filter from a motive compartment. Make sure that the filter is blown in both directions. In case of need make its replacement. Install the serviceable filter into place, having reliably fixed hoses by collars.
  2. On models of 4.2 l disconnect the line of supply of fuel from a gasoline tank from the inlet party of the fuel pump. Uncover a jellied mouth of the fuel tank and ask the assistant to listen to the sounds proceeding from a mouth. Blow to the fuel line in the direction to a gasoline tank. If passability of the line is not broken, the assistant will hear gurgle in a tank.

The check described above cannot be executed on models of 3.0 l as they are equipped with the electric fuel pump which is built in a gasoline tank equipped with the unilateral control valve. If after a clearing of the fuel filter supply of fuel is not restored, apply for more detailed information to the Section devoted to a power supply system and execute the corresponding check of serviceability of functioning of the electric fuel pump.

  1. Connect the fuel line to the fuel pump and check supply of fuel from the pump. If supply of fuel to the carburetor party of the pump is absent, one of the listed below refusals is possible.

Models of 3.0 l

Models of 4.2 l

Gurgle takes place, but supply of fuel from the pump is absent
The fuel pump is faulty. See the appropriate section devoted to diagnostics of malfunctions of the pump.

If fuel regularly comes to a fuel pipe from the carburetor party, and the engine is still not started, execute the following checks:

 PERFORMANCE ORDER

  1. Make sure that there was no carburetor flood owing to excessively intensive swing of the accelerator pedal in attempt to make start. Also make sure that the air gate is not jammed in a closed position if the engine is heated-up up to the normal working temperature. Consequences of the gulf of the carburetor sometimes can be eliminated by percussion on the float-operated camera around placement of the needle valve and its saddle (see an accompanying illustration).
  1. Turn out spark plugs and check whether electrodes are filled in with fuel. In case of need carefully wipe and dry candles before installation them into place.
  2. If the gulf of the carburetor takes place, check a float with the needle valve for existence of signs of jamming. Whether check also the float is punched that led to filling with its fuel.
  3. Check whether the filtering air cleaner element is hammered.
  4. If the gulf of the carburetor does not occur, and fuel regularly comes to it, the following is possible causes of failure:
    1. The fuel filter is blocked.
    2. The needle valve is jammed or blocked.
    3. The control valve is not closed properly.
    4. Leak of air in the inlet pipeline or through basic flanges of the carburetor owing to deformation or destruction of laying takes place.
    5. The hose of the vacuum amplifier of brakes is punched or connection between the amplifier and the inlet pipeline weakened.

The models of 4.2 l of late years of release equipped with system of injection of fuel (EFI)

In view of complexity of the device of the EFI systems authors of this manual recommend to the reader in case performance of the listed below checks does not allow to establish a cause of failure (the engine is still not started) to address for additional data the appropriate section devoted to diagnostics of malfunctions of systems of injection of fuel and engine management is lower in this Chapter.


 PERFORMANCE ORDER

  1. Make sure available of a gasoline tank of enough fuel.
  1. Press a hose of supply of fuel on the site on the middle between the fuel filter and the fuel highway (see an accompanying illustration) and ask the assistant to include ignition. The relay of the fuel pump has to publish distinctly heard click, and in a hose there have to be notable pulsations testifying to serviceability of supply of fuel a gasoline pump. At the low level of an external noise background it is also possible to hear through a jellied mouth of the fuel tank the hum published by the pump within about five seconds after inclusion of ignition.
  1. If the relay publishes click, but the pump does not function, check a safety lock of the fuel pump on 15 A in a relay box in a motive compartment of the car. If a safety lock as it should be, check existence supply voltage on pump plugs at inclusion of ignition for five seconds.
  2. If the relay does not click at inclusion of ignition, replace it.
  3. If the gasoline pump functions regularly, but pressure in a fuel hose does not rise, check passability of fuel lines and the filter. If after elimination of all revealed defects the engine is still not started, remove spark plugs and check them for existence of traces of fuel on electrodes. Carefully wash out and dry candles before installation them into place. If the gulf of candles does not occur, but the engine nevertheless is not started, address the Section devoted to diagnostics of malfunctions of systems of injection of fuel and engine management is lower in this Chapter.

Check of mechanical systems

The procedures described below are subject to performance in case the starter normally turns the engine. Otherwise squeeze out coupling for disconnection of the engine from the transmission (model with RKPP).

If the starter still cannot turn the engine, then not malfunction of transmission is a cause of failure, - remove a starter and try to turn the engine manually. Such check will allow to define whether the cause of failure in jamming or failure of a starter lies, or mechanical breakage of internal components of the engine, such as conrod and piston assemblies, a bent shaft, etc. takes place. If the starter as it should be and the engine is not turned manually, Address the Section devoted to diagnostics of the reasons of mechanical engine failures below.

It is necessary to remember that the only correct way of check of compression pressure in cylinders of the engine is check with use of a kompressometr. The method of check of extent of compression described below allows to estimate the general mechanical condition of the engine only rudely.

 PERFORMANCE ORDER

  1. Uncover a radiator and check the level of cooling liquid in it. If level excessively fell, attentively examine the power unit on existence of signs of external leaks. Take the probe of measurement of level of motive oil, and examine its edge regarding identification of signs of foaming of oil (see an accompanying illustration). If oil on an edge of the probe has a molochnoobrazny consistence, at simultaneous increase in its level, miss three following operations and you pass to performance of further checks.
  1. Cut off power system of ignition by a detachment of a positive wire from the ignition coil.
  2. Turn out all spark plugs, except for one.
  3. Include a starter and listen to the sounds made by the turned engine. Serially rearrange a candle in different cylinders, repeating check. The sound made during the operation of the cylinder with the lowered compression considerably will differ aurally. Besides, the serviceable cylinder will create the noticeable resistance to an engine provorachivaniye while the engine provorachivaniye with installed in the cylinder with the candle lowered by a compression will freely occur.
  4. If during above-mentioned checks leak of cooling liquid and presence of its traces at motive oil or on spark plugs is revealed, it is necessary to check a condition of laying of a head of cylinders, to examine the block and existence of cracks, and also to measure planeness of the interfaced head surfaces with the block.
  5. If during estimated check of extent of compression easing or unevenness of distribution of compression pressure is revealed, (she) should add to the list of the possible reasons listed in the previous paragraph defect of the piston and a burn-out or defect of the valve(s).
  6. If during performance of the listed checks signs of internal leak of cooling liquid are not revealed, continue the procedure of diagnostics, having executed the checks described below.
  7. Uncover the distributor of ignition and make sure that at the included starter the runner of the distributor rotates synchronously with the engine.
  8. Uncover a head of cylinders and at the included valve starter regularly open and closed during an engine provorachivaniye.
  9. Further, if the runner or valves do not function properly, the listed below options are possible.

The runner does not rotate, but valves function regularly

Neither the runner, nor valves function

If during the correct performance of all listed checks no aberrations are revealed, it is necessary only to check correctness of installation of a corner of an advancing of ignition and phases of gas distribution. It is necessary to notice however that if violation of installation of a corner of an advancing of ignition appears a cause of failure it is necessary to find out the reason of this violation, especially if till the last moment the engine was started and functioned regularly.

For check of installation of a corner of an advancing of ignition and phases of gas distribution it is necessary to uncover the distributor and a head of cylinders and to turn the engine clockwise for a pulley of a bent shaft so that the piston of the first cylinder fell into a state of VMT of the end of a step of compression. At the same time valves of the first cylinder have to be closed, and the runner of the distributor to turn a nose to a segment of VV of a wire of a spark plug of the first cylinder in a distributor cover.