Skip the auto shop - Our mechanics make house calls

Q: Idle speed control value

asked by on

Idle speed control valve is making it lose power
My car has an automatic transmission.

A: Hi, thanks for writing in. I’d be happy to ...

Hi, thanks for writing in. I’d be happy to help.

This is a case of an idle air control valve not working properly. An idle air control valve literally bypasses air around a closed throttle plate inside the throttle body so the engine can get air at idle. On start-up, the engine control module (ECM) or powertrain control module (PCM) checks engine coolant temperature, ambient air temperature, barometric pressure (on some engines) and then determines how much air and gas is required to start the engine.

The idle air control valve works at idle and during deceleration-- in other words, any time you take your foot off the pedal. During deceleration, the computers on most fuel injected vehicles perform a “fuel cut” procedure where the fuel injectors are forced to cut fuel to the engine resulting in RPM drop. However, since the pistons are still moving up and down, the engine still needs an air supply. The idle air control valve opens during deceleration to provide that air. This appears to be the problem you are experiencing. If you would like help, consider having an expert automotive technician from YourMechanic come to your home or office to inspect and diagnose this issue for you, and make any repairs as needed.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Engine idles rough and jumps between 500 and 1200RPM when shift from Drive to Reverse; Check engine light on

You may have a couple of separate issues: The flashing Check Engine Light under heavy load is most likely an ignition system misfire. This could be something like a coil pack or worn spark plugs. These engines are...

Q: Need some help with what headers to get and where they go?

Hi there. Headers are designed to take the place of the exhaust manifolds on your engine. Heaters are mounted on the cylinder head and connected to the exhaust pipe. Now, if your vehicle has exhaust manifolds and you want to...

Q: My truck started to vibrate, lose power, etc.

Hi. When your Check Engine Light is blinking during acceleration, this usually means that the engine is misfiring in more than one cylinder of the engine. The by the engine misfiring, it causes the computer to adjust how the engine...

Related articles

How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the P0052 code means This code is seen when the Engine Control Module (ECM) tries to control the...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.