Skip the auto shop - Our mechanics make house calls

Q: Car not accelerating and doesn't always start

asked by on

My car is not accelerating past 20 MPH. It goes very slow and shuts off when idling. The car also doesn't start sometimes and I have to sit and wait until it does.

Your issue sounds like it could be a failed fuel pump in its last moments of life. With lack of fuel the vehicle will run very poorly and will not be able to accelerate and won’t be able to run at idle unless kept running with the gas pedal. Your issue could be coming from multiple other things as well. The vehicle could be in what is called "limp home mode" which is where the computer controlling the engine management system sees a serious problem that, if left alone, could cause major engine damage. The computer will enter this mode to keep catastrophic failures from happening. A proper diagnosis of your accelerating issue should be carried out to find the cause.

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: Car jerks during quick acceleration

You may have a misfire in the engine or low fuel pressure from a bad pump, clogged filter, or both. I recommend having a mechanic test the fuel pressure and volume to see if the fuel pump is meeting specifications....

Q: when I have to start the car with the engine cold it doesn't warm up and I have to accelerate it myself for it to warm up

Hi Christopher. When the car will not idle on it's own upon start-up, it's typically due to a problem with the idle control valve on a fuel injected system. The Idle Control Valve is designed to control and maintain a...

Q: Truck shakes at high speeds

Hi there: To answer your question simply; YES, even slight damage to your sway bar linkage can cause severe shaking above 55 mph. You also indicated that the tire has a little play when you jack it up which might...

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...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...
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.