Unstable Car RPM When The AC Is Turned On

Unstable Car RPM When The AC Is Turned On, Check The Following 5 Causes

Unstable Car RPM When The AC Is Turned OnGnewscar.com– One problem that is widely complained of is that the Autoexpose reader is an RPM problem that fluctuates when the AC is turned on.

You might need to install it on the car’s AC system, remembering that the symptoms appear only when the AC is turned on. But that does not guarantee the truth, regulating the engine until the AC system is very complex. It could be from the engine itself.

Therefore today Autoexpose will explain what causes can affect the machine becomes unstable with the solution.

Unstable Car RPM When The AC Is Turned On

Unstable Car RPM When The AC Is Turned On

1. Idle Speed ​​Control Damage

Idle Speed ​​Control (ISC) is a component in the injection system that regulates the engine RPM at idle or stationary so that it remains stable according to workload.

Normally, ISC will set the engine RPM at 750-800 rotations per minute. But the engine workload is always changing, so that the ISC can set the idle RPM to 1000 RPM. For example when there is one spark plug that dies, and when the AC compressor is active it will increase the workload of the engine so that the ISC automatically raises the idle RPM.

But what if ISC has a problem?

Of course it will cause some symptoms, such as brebet engine at idle, until the engine RPM fluctuates when the AC is turned off or on.

If we connect the ISC damage with the AC turned on, of course there is a correlation, because ISC is the one who raises the engine RPM so that the engine does not turn off when the AC compressor is on. So when ISC has a problem, there will automatically be problems with the engine RPM when the AC is turned on.

However, this problem is still relatively mild because it only causes the RPM to fluctuate when the AC is on. Usually this is only due to a dirty ISC needle. So to fix it, we also only need to clean the ISC component.

2. Gas valve full of dirt

In addition to damage to the Idle Speed ​​Control, the car’s rpm up and down can also be caused by the condition of the throttle body that is full of dirt.

Then what to do with car air conditioning?

As we know that the gas valve is a component that serves to regulate the flow of air into the combustion chamber. In the Idle position, the gas valve opens very little because some of the air at idle will enter through the idle channel. But there is still air entering through the gas valve.

But what if the gas valve is clogged with dirt? this will cause the passing air debit to become unstable as a result the engine RPM will go up and down. Especially when the AC is turned on, the need for air becomes more so that it will feel very unstable when the AC is turned on.

Usually the dirt on the gas valve is caused by the effect of an air filter that is too dirty, or has never been replaced. It is true, there is an air filter cleaning interval usually around 10 thousand KM. But for those of you who are in a dusty area, the air filter becomes dirty faster, so you have to clean it more often.

To clean the air filter, just use a gust of wind while cleaning the gas valve, you need the help of a scale cleaner like a carburetor cleaner.

3. Intake leaked manifold

In the injection system, the amount of air entering the combustion chamber is calculated by air flow meter or mass air flow, this sensor is usually located after the air filter before the gas valve.

Data from the air flow meter is used by the ECU to determine how much gasoline the injector needs to spray so the engine performance is ideal.

But when there is a leak in the intake channel, especially after the air flow sensor, the story is different. This leakage will cause the sensor readings to be incompatible, because the sensor reads the air flow that only passes through the sensor while the amount of air turns out to be more because the air is sucked in through the cracked intake manifold.

This will cause the engine performance to be chaotic, so that problems such as unstable RPM can arise.

Then how to overcome it?

You need to find cracks in the intake manifold, if there is you need to replace the cracked part. In addition to cracks, connections that are not tight can also cause leaks.

4. Non-smooth circulation of freon

Which adds to the workload of the engine when the AC is turned on, it’s because of freon circulation. So the longer the freon circulation path, the greater the workload of the engine. But generally, freon circulation has been set in such a way as to be able to engine.

But the story is different if the freon circulation is not smooth, this will increase the workload of the engine so that when the air conditioner is turned on the engine receives more load as a result the engine RPM becomes unstable.

Freon circulation can generally be disrupted in parts;

Clogged AC condenser
AC compressor wear

Problem number four has entered the realm of the AC system problem so to check it needs the help of an AC manifold pressure tester to find out whether the freon AC pressure is stable or not. If there is a blocked circulation, the needle tester becomes unstable.

5. The engine idle up system has a problem

Above has already been alluded to, when the engine workload increases due to an active AC compressor, the ISC automatically increases the engine idle RPM, this is called the idle up system.

ISC itself is regulated by the ECU, while the standard ECU is the compressor and freon AC pressure sensor. So if the sensor is damaged, or the sensor cable is peeled off it can cause a mismatch in reading the data.

As a result, the idle up system will error so that the engine RPM will go up and down even off when the AC is turned on.

The solution Unstable Car RPM When The AC Is Turned On to the affairs of electrical systems like this is to scan using a computer.