Possible reasons why the car will not start.

В разговорах автолюбителей часто встречается фраза, в которой они сетуют на то, что The engine will not start. Если это случается нечасто (раз в месяц при ежедневной эксплуатации), то обращать внимание на это не стоит. Тем более, если вторая попытка запуска успешна. Другое дело, если после нескольких попыток машина полностью отказывается работать. В этих обстоятельствах у автомобилиста три варианта. Первый простой – бросить машину и ходить пешком, второй – вызвать эвакуатор и отдать машину в руки специалистов, и, наконец, третий – попробовать провести диагностику и устранение неполадок самостоятельно.


  • 1 Assessment of the current state of the engine
  • 2 Why does it not start?
  • 3 Starter Diagnosis
  • 4 Fuel Supply Diagnosis

Evaluation of the current state of the engine

the cause machine does not start

Often, you can independently identify the reason why the engine does not start.

Diagnostics of the engine in case of a difficult start or inability to start can be described by a rather simple algorithm. After completing this “program”, you will either start the engine, or you will have to call experienced specialists for help. These are the few steps:

  1. Check the status of candles.
  2. Diagnostics of the fuel filter.
  3. Assessment of the battery condition, reliability of the connection of its terminals, the level of the output voltage.
  4. Assessment of the state of the throttle. It should not have visible contamination.

Why does it not start?

Here are the most common reasons why the car does not start:

  1. Battery discharge. Determined using a voltmeter. If the battery voltage is less than 12 volts, the battery is discharged or defective. A very likely cause may be a poor fit of the terminals to the battery terminals. This is due to oxidation. In this case, there is also a small battery charge, which leads to its rapid drawdown and failure.
  2. "Dew" on high-voltage wires. This phenomenon leads to a decrease in insulation resistance and causes current leakage through it. The result is either the absence of a spark or the inability to ignite the combustible mixture in the cylinder.
  3. Traces of insulation failure of electrical wiring, moisture on the wiring harness, oxidation of contacts. As a rule, these faults are preceded by frequent blown fuses or failures in the electrical equipment of the car.
  4. Weak or missing spark. Check the candles, if necessary, put a new or known good. Pay attention to the ignition coil, try to replace it with another one (if possible).
  5. The presence of problems in the power supply system of the internal combustion engine. In this case, the intervention of specialists is necessary.
The engine will not start

The search for the reason why the engine refuses to start should be started by checking the spark plugs

Starter Diagnosis

If when turning the car key to the “Start” position, the car does not show signs of life, then the problem is simple - the starter relay or the Bendix is ​​faulty. In modern cars, especially in foreign cars, starters are very demanding on the quality of lubrication and extremely sensitive to ingress of dirt. The starter itself is a simple device and is easily removed from the engine. Understands the conditions of the workshop with the use of plumbing tools.

See also: Why the starter does not click and does not twist

Before laying a new lubricant, it is necessary to clean out the old one as best as possible, examine the starter for deformation, sticking, jamming. If nothing like this is found, the lubricant is replaced, the “Bendix” clicks, and the starter does not start, that is, it makes sense to contact the service.

If, on turning the key, there is no click of the “Bendix” - the relay is defective. It is usually located in the same housing with the starter. Therefore, together with the revision of the starter, the relay is checked. If the relay fails and it is impossible to repair it, the entire starter will have to be changed.

why the car won't start

The engine may not start if the voltage supplied by the battery is less than 12 volts.

Fuel Supply Diagnosis

If there is a spark, the starter turns, but the car does not start, then the problem lies in the fuel supply system. It consists of a carburetor (or an injector with an electronic control system), a fuel pump, a piping system, a fine filter and a fuel tank. With him and begin to check, or rather, to check the presence of fuel in the tank. Next, check if the filter is clogged. Next in line pump. In the case of an injection engine, the test takes place by turning on the ignition. You should hear the sound of the inclusion of the fuel pump. Surely every motorist easily recognizes a weak hum, which immediately follows the transfer of the key to the “Ignition” position. If this symptom is not present, then the problem is either in the pump or there is no signal from the motor controller due to its malfunction. There can not do without the help of car service.

The carburetor engine is equipped with a mechanical pump. It works from the camshaft. To test its performance, remove the fuel hose from the carburetor and repeatedly press the manual fuel injection lever located on the fuel assembly itself. From the hose should splash gasoline. The absence of spatter indicates either a pump malfunction or a lack of gasoline.

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Если после всех вышеописанных операций ответ на вопрос why the car won't startтак и не был найден, то, скорее всего, требуется настройка карбюратора (или ремонт инжектора с перепрограммированием контроллера). Эти операции должны проводить высококвалифицированные специалисты и в «домашних» условиях устранить эти неисправности не получится.