2.13. Diagnostics of malfunctions of the engine

If the engine is not started, it is necessary to look for the reason, systematically narrowing a search circle. In order that the engine in general could be started, two main conditions have to be satisfied. Air-fuel mix has to come to cylinders and on spark plugs the ignition spark has to slip. Check always should be begun with fuel supply existence. How to arrive in that case it is described in subsection

1. To define existence of a spark, to turn out spark plugs, to insert into the candle plug and to put them consistently to weight. At the same time it is not recommended to hold the plug a hand. It is necessary to use well isolated pincers. With assistance to scroll the engine a starter.
2. If the spark of ignition is absent see subsection 2.14.8.
3. At diesel engines to check system of preliminary heat of candles.


At diagnostics to pay attention to indications for safety measures at the handling of electronic systems of ignition (see subsection 2.14.2).

The engine is started badly or at all is not started
Petrol engine
Mistakes at start
To turn the ignition key and to start so far the engine will not start working only then to release the ignition key. During start the pedal of coupling has to be squeezed out. Not to give gas.
Only at the hot engine after start to add a little gas.
Diesel engine
Mistakes at start
On the cold engine: to take out up to the end the gate of the accelerator of cold start. To include ignition for a while, the control lamp of preliminary heat will not go out yet. To squeeze out coupling. At once after switching off of a control lamp to start the engine, not to press gas. As soon as the engine heats up to working temperature, to drown the gate of the accelerator of cold start up to the end. If the engine at start grabs irregularly, to continue to twist a starter (max. 1/2 min.) until the engine starts working independently. If the engine is not started, once again to make preliminary heat and to repeat start as it was described.
At the warm engine: does not need preliminary heat. The engine can be started at once.
The safety lock is faulty:
To check safety locks (see subsection 10.10).
  – electric fuel pump
  – electronic system of injection of fuel
  – systems of preliminary heat
The engine power supply system is faulty
It is polluted, the fuel-supply line is bent, littered the filter
To check an engine power supply system according to diagnostics of malfunctions.
Too slowly the starter rotates
To charge the rechargeable battery. If seasonal oil is filled in, it is necessary to fill in winter oil in cold season. To check a starter.
Too low pressure of a compression
To check hydropushers, to touch the engine.
Faulty operation of the mechanism of gas distribution
To check the gas distribution mechanism, to check a tension of a gear belt.
Laying of a head of the block of cylinders is punched
To replace laying.