Q: Q: Idle fluctuates and then stalls.

asked by on

just replaced rear valve cover. Now when I start the vehicle idles down and turns off. Idle reset maybe? Also thought tune up would take rough feeling from drive but when temp is at norm do not feel the rough drive

My car has 180000 miles.
My car has an automatic transmission.

Hi There, It sounds like you may have a dirty or failing idle air control valve causing your engine idle to fluctuate and eventually stall. The idle air control valve is a small valve on the engine’s intake system that reads the air intake as it comes into the motor. This is controlled by the car’s ECM which uses this information to make adjustments to the air/fuel ratio depending on various inputs such as outside air temperature, intake air temperature, load and various other things. As you accelerate, your car’s engine is receiving a much higher dose of fuel than when at idle and conversely, when you let off the gas pedal, there is a sudden change in this fuel supply as a result of your foot letting off the pedal. When this happens, the job of the idle air control valve is to bring this deceleration down to a slow and smooth idle rather than suddenly cutting off the fuel supply causing the motor to die. When the idle air control valve is not working properly, this cause a disruption in this process resulting in the engine not being able to idle properly. I would recommend having a professional come to your location to diagnose and inspect your vehicle.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. Q: Idle fluctuates and then stalls.

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: What is the vehicle information display?

Your central gauge cluster is where you’ll find vital information about your vehicle and its operation. Everything from the speed at which you’re traveling to whether or not cruise control is active can be found here. You’ll also find the...

Q: I bought camshaft position sensor off of eBay and car is cutting off a lot. Still has check engine light for camshaft position sensor

Hello, thanks for writing in. From my experience with eBay sensors, chances are that it is bad. This happens all of the time with these sensors. A bad crank position sensor can also cause this as well as a failing...

Q: Possible bushel, arm control, or rotor problem.

Does it make the noise over bumps or all the time while your are moving? Is it a single clunk or a rattle type sound? If it is a single clunk or a rattle over bumps it could be a...

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...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...
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.