Q: Car suddenly stops accelerating.

asked by on December 03, 2016

When accelerating, sometimes my car will stop and continue going at around 40 mph. No matter how much I press the gas it wont accelerate. Just stay going 40 mph. It's as of it gets stuck in the 2nd gear or something. This is scary when going down the highway. After letting off the gas and slowly accelerating again several time it will grab and start going again. What's causing it to stop accelerating or maybe causing the 2nd gear to get stuck?

My car has 88000 miles.
My car has an automatic transmission.

Throttle Position Sensor Replacement $129.21 - $646.10 Get a Quote
Mass Airflow Sensor Replacement $171.84 - $740.29 Get a Quote

This may be related to a faulty throttle position sensor or potentially a dirty or failing mass air flow sensor. The mass air flow sensor is a unit in the intake system that monitors air intake as it is mixed with fuel prior to being injected into the motor. When this is dirty or faulty, this causes an imbalanced air/fuel load to be supplied to the motor which results in an over fueling or under fueling situation depending on the conditions. This type of inconsistent fuel supply to the motor may cause a hesitation, loss of power, a jerking reaction, potentially a bit of black exhaust smoke and typically a strong smell of fuel when this sensor is malfunctioning. When this is not working properly, you may also notice a strong smell of fuel.

The throttle position sensor (TPS) 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. Based upon the inputs from the sensor reading your foot’s position on the pedal, the ECU then makes the direction to supply more or less fuel to the motor. When this sensor is not working properly, this can cause intermittent responses when pressing the gas pedal as you have experienced. I would suggest having a professional from YourMechanic come to your home to diagnose your vehicle’s running condition.

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

What others are asking

What manual transmissions will fit in my car?

Hello. Unfortunately there are really no other transmissions available that will fit into your vehicle and still have everything else work properly. If you tried putting one of the transmissions prior to this one then the axles are not going...

Oil pressure repair cost, Oil Light comes on, and Check Engine Light is on - code P0022

Car went backwards when I had it in drive.

This is a known issue in the Volkswagon Jetta transmission. Converter drain back is a situation where the automatic transmission fluid drains back into the transmission pan causing this kind of a reaction. Some of this is normal, but not...

My car won't engage 1st gear 2006 Audi A4

Hi there - I believe the problem is more likely with the 1st gear set in the transmission. If the clutch works in one gear, it will work in all gears. While a bad flywheel would cause the vibration and...

Squeaking when you hit a bump in the road

You should check the sway bar bushings and links. You can do so by having someone bounce the car up and down and have the other person feel them by hand. You will be able to feel squeaking part. ...

1999 VW Jetta Poor acceleration

The check engine light tells you that the Engine Controller (ECU) has detected a fault and stored a trouble code. So the best place to begin is to have the codes read and interpreted bu a technician. It's possible you...

Runs fine when cold- after 1/2 hour or so , spits and sputters then quits

Hi and thanks for contacting YourMechanic. To me this symptom sounds like three different problems that could be happening. One problem is that the Engine Gas Recirculation valve (EGR valve) could be stuck open. This will cause the exhaust...

New car oil consumption before 1st oil change

Hi there. Either the positive crankcase ventilation valve (PCV) or the turbo has excessive oil blow by. Check the PCV valve and see if its working. Check the air filter to the engine and make sure that its dry and...

vehicle won't turn on or start.

Hi there. Check the battery and see if it has a full charge. If the battery has a full charge of 12.6 volts, then put a load tester on the battery and check to see if the battery will hold...

Related articles

A Buyer’s Guide to the 2012 Volkswagen Golf
The The 2012 Volkswagen Golf offers comfort and an elegant design for a variety of transportation needs. The Golf is a solid vehicle, good size, and great value, especially when it comes to comparing prices of similar vehicles. Key Features...
What Happens to Sensors if They are Dirty?
Car sensors can get dirty with normal use. Symptoms of dirty sensors include reduced engine power, worse gas mileage, or an engine that hesitates.
What Sensors Do All Cars Have? And What Optional Ones Are There?
Modern cars have an increasing amount of sensors. Most cars have an oxygen sensor and a throttle position sensor, but parking sensors are optional.