Q: Poor acceleration and rough idling at times.

asked by on

Truck is idling rough at times and has poor acceleration and sometimes none at all. Replaced plugs, wires, pcv valve, fuel filter and pump. New muffler and cat. Starts up fine but driving it is almost impossible. It acts like it isn't getting fuel properly and when it starts sputtering if I floor it, it just quits altogether.

My car has 160631 miles.
My car has an automatic transmission.

This may be related to a dirty or failing idle air control valve, or throttle position sensor.

The idle air control valve is a unit that reads the air intake as it is mixed with fuel, prior to being injected into the motor. The computer uses this information to make fueling adjustments. When this valve does not work properly, it may cause an over-fueling or under-fueling situation, depending on the conditions, which may cause a rough idle or poor acceleration.

The throttle position sensor is a sensor used to monitor the throttle position of the throttle plate inside the throttle body in relation to your foot position on the gas pedal. The sensor is usually located on the throttle plate so that it can directly monitor the position of the throttle. The ECU then makes the direction to supply more or less fuel to the motor. When this sensor is not working properly, it can cause intermittent responses when pressing the gas pedal.

It is recommended that you get a professional technician, such as one from Your Mechanic, to come to your location and diagnose your throttle control system and replace the idle air control valve, if needed.

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. Poor acceleration and rough idling at times.

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: My 2010 Ford Escape vibrates a lot. There are no leaks at all. What could be the cause?

If the vibration happens when you're stopped at a red light, then it's more than likely caused by a vacuum leak, or fuel or ignition system component failure. Typically, the first three parts that would be inspected are the idle...

Q: Q: Car not going over 20 MPH

Hello. If the car will not go over 20 MPH then there can be a number of issues going on. If the Check Engine Light is on then the computer needs to be scanned for codes first. If there are...

Q: There appears to be a short causing the battery to drain while the engine is off

Hi there, thank you for asking a question about your 1993 GMC K2500 Suburban. The easiest way to find the source of battery drainage is by process of elimination. Get a hold of a volt/multi-meter. Start with a fully charged...

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...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
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...