Fluctuating engine speed. What is it and how do I fix it?

You stand relaxed, and the engine of your car, instead of a quiet and delightful rumbling, makes disturbing sounds. In addition, the revolutions spontaneously rise and fall, like on rollers, moving the tachometer needle up. Cause for concern? What could be their fault and how to deal with it?

What will you learn from this post?

• What does swinging engine speed mean?
• What are the causes of wavy engine speed?
• What to do if the engine runs unevenly at idle speed?

Shortly speaking

The most common causes of undulating idle are mechanical defects, such as damage to the stepper motor, and electronic failures - sensors, cables. Sometimes the reason is prosaic: a dirty throttle from which the computer incorrectly reads data on the amount of fuel supplied to the engine. In other cases, you will have to fight to find the culprit.

Why is the rotation swinging?

Because the control unit wants good. When the on-board computer receives any readings from any of the sensors in the car that could affect the operation of the engine, it immediately responds to them. Also when they are wrong. And when, in a moment, he receives completely conflicting information from another sensor. He listens to each and every one of them properly. corrects engine operation, sometimes increasing and then decreasing speed. And so again and again, until you shift into gear - everything seems to work perfectly when accelerating - or ... until the damaged component is replaced.

Leaks

If you notice any disturbing symptoms of a rotation wave, first check electrical wires, spark plugs and ignition coils... and in the second tightness of the intake manifold and vacuum lines! Sometimes it is a leak that causes an uneven engine operation, into which air enters the world, thinning the fuel mixture. Confusion occurs especially when air enters the circulation after the flow meter. Then the computer receives conflicting data from the beginning and from the end of the system, that is, from the lambda probe, and tries to forcibly stabilize the engine.

Broken stepper motor

The stepper motor in a car is responsible for controlling the idle speed, and it is its failure that usually causes idle fluctuations. Dirt is the enemy. Cleaning tarnished contacts wires should help. If the problem is more serious, such as a burned out component or a burned out idle valve, you will need a stepper motor. replace.

Dirty choke

Although it is controlled by a stepper motor, it is from the throttle valve to the powertrain control unit that one of the most important data in the car's circuits is transmitted: information that the driver has just pressed the accelerator pedal. Of course, provided that a layer of dirt has not adhered to it, which interferes and interferes with proper operation.

Throttle body is enough чистый with a special fuel system cleaner. To do this, you must first disassemble the filter and air duct, and then pour the drug into the throttle valve. The second person at this time must operate the gas pedal in such a way as to maintain a constant speed. Of course - on a running engine.

When you're done cleaning the throttle body, don't forget about your computer. calibration her.

On-board computer

The younger the car, the more likely it is to blame. electronics... Strictly speaking, we are talking about incorrect readings of sensors controlling the ECU, such as a lambda probe, a crankshaft position sensor, multiple temperature sensors, a throttle position sensor or a MAP sensor. When any of the sensors fails, the computer receives incorrect, sometimes conflicting data. The biggest problem, of course, arises when the sensors fail for a long time and the computer does not correctly control the engine.

In the workshop, a service technician will connect diagnostic device into the brain of your car to find out where the problem is.

LPG installation

Gas powered vehicles more sensitive and receptive on the ripple of rotation. Especially if something went wrong during the assembly ... gas reducer... In order not to damage the engine, its adjustment must be carried out by a service department with an exhaust gas analyzer. If the adjustment does not bring the expected results, it will be necessary to replace the damaged gearbox.

Is the engine wobbling when idling? Fortunately, the Nocar store is running smoothly, so you can enjoy your trip without any problems. Look for spare parts or maintenance products for your car at autotachki.com!

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