Services
Insurance
Loans
Repairs
Advice
About

Why does my car stop accelerating when driving?

Today as I was driving up a hill and my car had a really hard time accelerating and getting to the top. What could be causing this?

avatar
Jason Tushinski · Updated on
Reviewed by Shannon Martin, Licensed Insurance Agent.
A car that won’t accelerate is usually suffering from a minor issue—not necessarily a major one. Odds are one of the following components is to blame: the mass airflow sensor, the oxygen sensor, the throttle position sensor, the fuel filter, air filter, or timing belt.
  • Mass airflow sensor blockage or malfunction: This little do-hickey measures the air mass going into the air intake. If the sensor is faulty or there is a clog, it can send the wrong data to the engine’s electronic control unit when calibrating the engine’s air-fuel mix. If that mix is off, the car won’t accelerate.
  • Oxygen sensor malfunction: If the oxygen sensor is damaged, your car won’t know what air-fuel ratio is correct to power the engine. If this is the case, you won’t be able to accelerate.
  • TPS malfunction: If your car’s throttle position sensor fails, it can result in your accelerator pedal being unable to control the engine’s speed. You won’t be able to control how fast you go, whether you hit the accelerator or not.
  • Clogged fuel filter: If the fuel filter is clogged, your engine won’t get the amount of fuel it needs to perform as it should—and you might not be able to accelerate.
  • Clogged air filter: Your engine’s air-fuel mixture needs the correct amount of clean air to function properly. If the air filter is blocked, the air-fuel mixture will be off and your car won’t accelerate properly.
  • Timing belt: It’s all about timing, isn’t it? In your car’s case, it is! If your engine’s timing belt is off even slightly, you’ll have serious problems accelerating.
Keep your car protected while on the road with a robust and cost-effective
car insurance
policy from
Jerry
. Jerry compares rates from more than 50 insurers to find you the best deals—then handles the switch from start to finish.
View full answer 
WHY YOU CAN TRUST JERRY
Jerry partners with more than 50 insurance companies, but our content is independently researched, written, and fact-checked by our team of editors and agents. We aren’t paid for reviews or other content.

Join 4M+ members in lowering their car insurance

Easiest way to compare and buy car insurance

√
No long forms
√
No spam or unwanted phone calls
√
Quotes from top insurance companies
Find insurance savings