Why does not the car start hot?

Often, the engine is difficult to start in the winter, when the temperatures on the street are very, very low. However, it often happens that carburetor engines start showing their "whims". It happens that the engine does not start on the hot one. So, if you stop and stand for a few minutes, you can not start a car anymore.

Car enthusiasts with experience often know all the features of their car and also know the different ways and methods of starting the engine in a variety of conditions, but most, and this is many beginners, with such problems for a long time trying to starter, battery, their nerves, but the machine does not react.

Typical reasons for the difficult start of the carburetor machine

If the car suddenly does not start on hot, then with a clever approach the problem can be completely solved. Here it is necessary to understand that when the engine is running, a huge amount of air passes through the carburetor. As a result, the carburetor cools. The same effect can be caused by fuel, which also passes through the carburettor. The result of this - during operation, the temperature of the carburetor will always be lower than the engine, and certainly lower than the boiling point of gasoline.

However, this situation will continue as long as the motor is running. If the car is stopped, the temperature of the carburettor will start to rise from the hot enough motor housing. At this point, there are no more air flows, so it will not be cooled. The gasoline remaining in the float chamber will become very volatile as the temperatures rise.

Fuel vapor will fill any cavities to which they can reach. It can be an intake manifold, a carburettor directly, an air filter and other parts. The levels of fuel remaining in the float chamber will drop below their norm, and sometimes so-called gas plugs in the power system may be formed.

How long this process will last depends entirely on how the particular car's fuel system is arranged, on the temperature of the engine and on the temperature overboard. Also, other factors can influence the duration. So, this effect can last 5 minutes, and 30 minutes.

If the driver during the passage of these processes suddenly wants to start a car, then because of the huge volume of fuel vapors that have accumulated in the cavities of the intake manifold, too much fuel will enter the cylinders. This is the main reason why it does not start on a hot engine.

Causes of poor start-up of injection and diesel engines

If everything is very clear with carburettors, then with injectors and diesel units everything is more complicated. There are many more reasons. This can be due to the fault of the coolant sensors, air flow sensors , problems with the injectors. Also, the hot one is not started often due to faults in the fuel pump, malfunctions in the ignition module.

Injector

So, the machine does not start hot. Among the most popular reasons, a coolant temperature sensor is distinguished. If it is out of order or gives incorrect readings to the ECU, the combustible mixture is not fed correctly. This reason is relevant for both the diesel engine and the injector.

Next, they give out injectors that can pass fuel. When they are in a free state, the vapors are formed, the mixture is re-enriched. As a result, it does not start on a hot injector. To check the injectors, you need a stand. But if it does not, you can check the state of the candles. To do this, the candle is twisted and carefully studied. With a leakproof nozzle, the candle will be dry. To solve this problem, it is necessary to change the injectors. Some try to clean them - this is not a panacea. To start a car with such a malfunction, it is necessary to open the throttle valve. This is done to purge fumes of fuel and relieve pressure in the fuel line. This reason can also occur if the sealing rings fail on the nozzles. Nozzles are one of the most popular reasons if the machine does not start on a hot one.

Disease diseases

On diesel engines, it is often impossible to start a hot motor due to a broken fuel pump. The main symptom of such a breakdown is a worn plunger pair. The same symptoms can be observed if the OPV valve is faulty. To exclude any suspicions on the plunger, the rear end of the high-pressure pump is cooled, and also tries to start the car. If the car can be started, then the problem is in the plunger.

Also, the machine does not start on a hot, if worn out bushings and packing glands of the drive shaft of the high-pressure pump. Under the stuffing box there is a space from which air is sucked into the pump. This does not create the necessary pressure in the plunger chamber. In order to cure this, they change the stuffing box and bushings.

Some diesel units are not started with the control nozzle, which is equipped with a temperature sensor, which is responsible for creating a mixture of air and fuel. If this sensor is broken, then the injection work is significantly impaired. This problem is solved by replacing this part.

It is not uncommon that the diesel for hot does not start because of the extended pump drive. As in the case of nozzles, this changes the angle of fuel injection. Only correction can help here. For this, the pump simply rotates a few degrees relative to the body of the device.

Hot motor stops

This is another very unpleasant moment. It is especially typical for the domestic automotive industry of the old years of production. If the engine suddenly overheats, it suddenly stops. Often this happens in the hot summer.

Among the popular reasons is the gas plug in the fuel pump. These plugs do not allow the pump to function normally, and the float chamber is dry. There the combustible mixture simply does not fall. In this case, only the cooling of the pump will help. It is watered with water.

With these devices you should be more careful. The pump housing can contain glass parts. When the temperature drops sharply, glass caps often burst. If the cooling does not solve the problem, the pump needs either repair or replacement.

Starter and problems with it

Many people are faced with the fact that the starter does not start hot. He turns, but does not cope with his task. These problems are very often discussed in profile forums.

The first thing that can come to your mind is a battery that has become dormant. However, often after testing it turns out that the battery is fully healthy and normally charged. Here you can search for problems in the starter itself, its power circuit or wiring.

Why the starter does not work well

In the event that it does not start on a hot VAZ, it may be a battery. Often, drivers leave their cars and do not turn off the headlights. Here, the battery can discharge very quickly, especially if it is old. Also check the terminals.

Further the starter can not start the engine because of early ignition. The symptom is tested as follows: pull the wire out of its coil and try to twist the heated engine without creating a spark. If the rotation is not difficult at all, then the ignition should be adjusted.

Check the brushes

Another reason is worn brushes or starter bushings. When the brushes have more wear than recommended, they can no longer reach the collector. This can be one of the reasons why the hot one does not start. If the wear sleeves are too strong, the armature touches the stator due to heat, and a short-circuit occurs which can reduce the speed of the starter. Here, for the diagnosis, you should ring the anchor with a multimeter. Also check interturn closures. The next reason is an incorrect set of bushings. When they heat up, they jam. Here it is necessary to pass the bushings with a reamer or to process them with sandpaper.

A typical problem is the ignition switch

The castle is very often to blame for a bad start. To diagnose it, check the contact group of the lock. Sometimes motorists mount a second relay to reduce losses in the lock chain.

The retractor relay may not work on the starter. A malfunction can be detected by ear. When you turn the key, there will not be a distinct click. The relay can easily be replaced. Next, check the condition of the terminal wire of this relay, and also check the integrity of the wire that connects the starter and the battery.

Check the engine

It happens that sometimes one or more liners are rubbed on the crankshaft. When the engine is cold, the starter perfectly untwists it, when the engine warms up sufficiently, the liner clamps crankshaft. It also happens that, due to the wear of the axle displacement liner, the crankshaft itself is displaced from its axis. Correct all these problems can only repair.

How to make a hot engine run well

To do this, it is necessary to deplete the fuel mixture to normal. At the time of starting the hot motor, the gas pedal is squeezed out to half. Sometimes it even happens that it is necessary to squeeze the pedal completely. If you press and release the pedal several times, you can not improve, but, conversely, worsen the situation. The pump will send the fuel mixture more and more, even more re-enrich the mixture. In this case, starting the engine will be very problematic.

Beginners drivers, having traveled by car, begin to understand it better, and then such problems do not arise. After starting the engine with a few clicks on the accelerator, the machine will run without problems.

This is practically all that can be said about this problem. If you do not get hot, there may be other reasons, but you know the main sources and you can diagnose your car yourself.