Skip the auto shop - Our mechanics make house calls

Q: idles rough after heavy acceleration, going up hill, getting off freeway, weak warm start ups

asked by on

My car idles rough after heavy acceleration, going up a hill or getting off the freeway. It runs normal after a few minutes of slow easy driving and accelerating is smooth. Also my warm start ups are weak. When the car starts up cold there is not problem but after the car is warm it hesitates when starting up.

The most common cause of this is either a charging system issue, such as the alternator or battery, or low fuel pressure from a clogged line or failing fuel pump. Either the charging system or the fuel system can have low output once the vehicle warms up and is under heavy demand. They may seem to work under normal condition, but once anything more demanding is required, the faults become visible. To have this checked, a qualified mechanic from YourMechanic will have little trouble diagnosing your acceleration issue and performing any repairs required.

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

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!
  1. Home
  2. Questions
  3. idles rough after heavy acceleration, going up hill, getting off freeway, weak warm start ups

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: drop into gear engine revs out of control

This is often times a sign of a vacuum leak. There is a plate that is supposed to be closed when the engine is cold to preheat the air going to the throttle body. As the engine warms up this...

Q: Tugging while shifting from first to third gear, the engine lacks power

Hi there. The most common cause of this is a bad catalytic converter. When it fails, it will clog internally and will restrict the exhaust. This will cause a serious lack of power like what you are experiencing. It can...

Q: Hose replacement due to overheating.

If your vehicle is overheating I would first recommend checking your coolant level. The information on how to do this can be found in your owners manual. Make sure the vehicle is cooled down before checking your coolant level. Low...

Related articles

P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
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...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.