Why does the car gas for no reason? + 11 main reasons
According to the online economy report, the mechanic wrote: It might not be bad to first provide a simple and brief definition of the concept of car biting. By driving a car a few times, you can notice its acceleration power. In simple words, you find out how the car’s acceleration changes when you press your foot on the gas pedal at a certain speed.
Sometimes it happens that the result of gas is the opposite of what you expect. In other words, whenever you press the gas pedal, you don’t see the acceleration of the car. This is what is commonly known as car biting.
What is the cause of car biting?
Apart from what is the reason for the car biting, you should note that this will cause problems while driving. In addition, it has a great impact on the drop in car prices in the second-hand market. For this reason, we suggest that you check this issue before buying or selling a car. 11 causes of car biting are:
Damage to the stepper motor
Brake system jamming
Damage to the gas valve or its sensor
Car gas pedal problems
Car map sensor damage
Disruption of air intake manifold sealing
Damage to the engine speed sensor
Vehicle ECU problem
Injector damage
Problem in the gas pump of the car
Trouble finding the clutch wire
Finding a solution to some of the causes of car stuttering is not that complicated. Instead, there are some other problems that can only be solved by expert repairmen. In this section, we will examine each of the reasons for the car biting separately.
1. Damage to the stepper motor
Usually, when you go to the repair shop first thing in the morning in search of the cause of the car gassing, the first thing checked by the repairman is to check the condition of the stepper motor. Stepper is an actuator in the car engine that adjusts the amount of air entering the engine.
The story is that the engine unit receives information from various sensors such as the valve shaft position sensor, engine speed, throttle position and oxygen, etc. while the car is on. Then by processing the information, it detects the condition of the engine. Based on the driver’s behavior, the motor unit issues the necessary command for the stepper to function. For example, when you press your foot on the gas pedal, there is a need for more air in the engine. So the stepper allows more air to enter the engine.
It is natural that the damage of this part will cause problems. For example, the car is turned off in situ. Also, at high engine speed, stepper failure is the most important cause of the car stalling. Usually, in this situation, there is no way to solve the problem except to replace the stepper. The problem may not be solved even after replacing the stepper. If you are curious to know the reason why the car bites after replacing the stepper, follow the rest of the text.
2. Damage to the gas valve or its sensor
Sometimes the cause of the car not moving is the failure of the gas valve sensor. This sensor is one of the important parts in the fuel system of the car. Its task is to measure the degree of opening or closing of the gas valve in injection engines. The data generated by this sensor is provided to the ECU of the car.
By checking the received information, the car’s computer finds out what state the engine’s throttle is in. As you know, the gas valve opens when you press the gas pedal and starts to close when you release it.
In such a situation, if the throttle sensor is damaged, the information will not be provided to the ISU correctly. As a result, this part does not issue the correct command according to the need of the car to move. For example, in stationary mode, the command to open the valve may not be issued by pressing the gas pedal. For this reason, sufficient oxygen does not reach the combustion chamber and practically the car does not move.
Of course, you should note that the problem is not always related to the throttle sensor; Rather, sometimes it is the throttle that breaks for any reason. In this case, the gas valve practically remains fixed and pressing or not pressing the gas pedal has no effect on changing its status. Sometimes, the cause of the car gassing when idling is the failure of the engine throttle.
3. Car gas pedal problems
The cause of a running car being bitten may be a broken gas pedal wire. Although this is very rare; But it usually happens to worn-out cars that have passed their useful life. The breaking of the pedal wire during movement makes it impossible to send a message to ISIO and Moto by pressing the pedal. As a result, you will see the speed decrease and even turn off the car.
Sometimes we may also see the gas pedal stiffening. This is easily determined by pressing the pedal. In such a situation, the gas pedal wire usually cannot perform its mission properly. For this reason, by pressing the pedal, you will see the car bite. If the problem is with the tuning of the pedal string, it can be readjusted. Otherwise, you need to replace the pedal wire.
4. Car map sensor damage
MAP sensor is another sensor that measures the amount of air entering the engine. This sensor is directly connected to the ECU. Sends measured data to ISIO. By receiving this information and data from other sensors, the car’s computer carefully controls the condition of the engine’s air valve. The MAP sensor is only available in injection vehicles.
Damage to this sensor may disrupt the opening and closing of the engine’s air intake valve. As a result, you will see Pride, Tiba, etc. cars being bitten while moving. Usually, the map sensor is not repairable, and in case of failure, you should consider replacing it.
5. Disruption of air intake manifold sealing
If you see the car stuttering in place or while moving, you should not always be sensitive to the failure of the stepper or the sensors that are located near the air intake manifold valve. Sometimes the problem is directly with the manifold.
As you’ve probably figured out by now, the intake manifold directs air and fuel into the engine’s combustion chamber. It is very unlikely that the manifold body will be punctured; But there is a possibility that the seal will be messed up at the junction of the manifold and the cylinder head. Gaskets are used for sealing, which are exposed to corrosion over time. If this happens, the air entering the engine will be different, which is sometimes the reason for the car to bite.
6. Damage to the engine speed sensor
The engine speed sensor is an important part in injection vehicles. This part plays a decisive role in adjusting the car’s ignition timing. The engine speed sensor measures the position of the piston and the rotational speed of the crankshaft. Then it sends this data to ISIO in the form of a signal. Based on this information, the ECU detects when the piston is at top dead center and instructs the spark plugs to fire at that moment.
Sometimes, the cause of the car biting while changing gears while moving is the failure of the engine speed sensor. This event causes the car’s ignition timing to be practically disrupted. For this reason, you may see a moving car being bitten. The engine speed sensor is also not repairable, and in case of failure, you must replace it.
7. Vehicle ECU problem
In some cases, the reason for the car biting is not the damage of different sensors. Rather, the brain of the car, i.e. ECU, may have a problem. In this case, the sensors send the data related to the status of different parts of the engine to the ISU correctly. But the ECU is not able to process the information properly. As a result, you cannot issue appropriate commands to adjust the performance of different parts of the car. This situation leads to many problems, of which being bitten by a car is only one of them.
8. Injector damage
The cause of the car gassing when starting can be the failure of the injector. Car injector is a mechanical or electromagnetic part that is responsible for injecting fuel in the form of tiny droplets inside the combustion chamber. In this way, the fuel and air are well mixed together, and as a result, a high-quality fuel mixture is obtained for combustion in the engine.
Injector failure causes fuel and air to not mix well in the combustion chamber of the engine. As a result of this, the engine efficiency decreases. When the problem worsens, the injector may not actually inject fuel into the combustion chamber. As a result, the car starts at first and then shuts off very quickly.
9. Problem in the gas pump of the car
The reason why Tiba, Quick, and other Iranian cars are gassed may be related to the problem of delivering fuel to the injector. When the vehicle is running, regardless of whether it is stationary or moving, there must be a continuous flow of fuel from the tank to the engine.
This is the responsibility of the car’s fuel pump. If for any reason this part has a problem, the fuel flow will not reach the engine in a stable manner. In this situation, it is normal that no matter how much you gas, the car does not accelerate. Because practically no energy is provided to move the car.
10. Trouble finding the clutch wire
The main cause of car gas when clutching is the problem of finding the clutch wire. It is possible to tighten or break this wire in different conditions. This is the wire that plays the role of the interface between the clutch pedal and the car’s power transmission system. In such a situation, it is normal that the failure of the clutch wire makes the power transmission in the car different. One of the problems that this issue brings is the biting of the car.
11. Brake system jamming
The cause of the car stuttering when braking is the jamming of the brake system parts. This problem occurs for various reasons, such as excessive wear of the pads, problems with the brake booster, air infiltration into the brake oil, or brake system components not being adjusted. However, the dangers of brake system parts being stuck are much more serious than car biting; But you should note that car bites are an important sign before more serious accidents occur.
Car biting happens in which cars more often?
As I mentioned in the introduction, the problem of car biting occurs much more often in domestic cars than in imported cars. After all, the more a car works, the more likely this problem will occur.
One of the issues that need to be mentioned here is the car biting after washing the engine. As you have seen, many car sensors play an effective role in preventing it from biting. These parts are electrical, and for this reason, there is a high possibility of damaging them during engine washing. We suggest that if you intend to wash your car engine for any reason, you should definitely go to reputable and professional car washes in this field.
What is the solution to being bitten by a car?
We examined the most important problems that cause the car to bite. Your behavior as a driver is one of the important factors in preventing damage to the main parts of the car. Therefore, try to always follow the specialized principles for taking care of different parts of the car while driving.
After that, periodically going to the repair shop to check the health of various electronic parts such as sensors will help you to prevent the car from crashing as much as possible. In many cases, if the parts are damaged, it is not possible to repair them and you have to think about replacing them.
final word
In this article, we examined 11 causes of car bites. The fact is that during several years of driving, you should prepare yourself to face the problem of car biting. It is rare to find a driver with a history who has not experienced such an incident. The main thing is to go to the repair shop before more serious problems occur when you see the car biting to find a solution to the situation.