Today we will tell you why a car can have these two engine problems, either accelerating or decelerating for no apparent reason. In many occasions our car has a behaviour that may seem strange to us and that in a certain way we could not know what is wrong with it and if the situation is serious or not and even if its repair will be costly or perhaps something that we can do ourselves with some patience. Let's start with the fact that there are cars that surprise us because they slow down on their own, for no apparent reason, although there could be several of them or because of idling problems.
It is important to define that the term idle speed refers to the minimum speed at which the operation of an internal combustion engine can be kept stable without requiring acceleration or fuel. Idling is generally not strong enough to move the vehicle, but it can operate systems such as lubrication, cooling or electrical systems, basically the method that in past generations of cars was known as "warming up the car", i.e. starting the car and allowing it to carburet and the lubricants and fluids to take on their necessary circulation and consistency.
The normal speed at which a vehicle idles is usually between 700 and 1,300 revolutions per minute, depending on the type of vehicle, as buses and trucks idle at lower revolutions, on the engine temperature, which will be higher at lower temperatures, and finally, on the systems connected to the vehicle.
Idling is very important for combustion vehicles, and it is very easy to notice when something is not working properly, just by observing for a few moments the behaviour of our vehicle at idling speed. Sometimes, idling can become unstable, and the revolutions can rise and fall randomly, and the vehicle can stall if it is not accelerated.
The IAC is controlled by the ECU, it regulates the amount of air flow in the throttle body to achieve idle speed. If your car slows down, it may be due to a problem with this valve. For this cause we will find that the engine shuts off at idle, there are vibrations or oscillations in the revolutions, which implies three very simple solutions, such as problems due to dirt, for which it is required to disassemble and clean the IAC; disassembly problems, which require disassembly, cleaning and lubrication.
