10 reasons your car won't accelerate

It’s hard to notice certain problems with your vehicle. A problem with your car’s acceleration is something harder to notice. If you are experiencing this problem and are having trouble locating the cause, there are more common causes of this problem.

For Starters, a clogged or malfunctioned Mass Air Flow Sensor will cause issues for a vehicle’s acceleration. A clogged or bad mass air flow sensor can send the wrong data to the engine ECU for calculating the air-fuel mixture. A warning sign for a vehicle that’s experiencing an issue with the air-flow meter is a vehicle that cannot accelerate properly.

The next possibility is the oxygen sensor. The oxygen sensor monitors the exhaust emissions of the vehicle. Your vehicle needs the correct amount of fuel to burn properly in the combustion cylinders. This helps your vehicle accelerate properly. If the sensor gets damaged, then the engine of that vehicle cannot figure out what ratio of the air-fuel mixture to use. This issue can cause your vehicle to experience slow acceleration.

Another possibility could be an issue with your vehicle’s. The TPS is your vehicle’s throttle position sensor, which detects the throttle valve opening angle. If there is an issue with your vehicle’s TPS, the engine speed cannot be controlled by the accelerator pedal. This will allow your vehicle’s engine speed to increase or decrease uncontrollably. Because of this problem, a TPS malfunction can be a likely candidate for why your vehicle cannot accelerate.

Or it could be an issue with your vehicle’s fuel filters. Your fuel filter help gives your engine enough fuel to accelerate properly. If your vehicle’s fuel filter is dirty or clogged, this will prevent your engine from getting enough fuel. This can cause your vehicle to experience problems while trying to accelerate. A dirty air filter can also be the culprit.  A dirty air filter cannot give the right air-fuel mixture resulting in slow acceleration.

Another possibility can be a problem with the timing belt. The timing belt attached to the engine can cause issues with your vehicle’s acceleration. If the timing belt is placed incorrectly, it can cause the problem of a vehicle not accelerating properly (auto-technician, 2019). Or it could be an issue with the fuel pump. A defective fuel pump will not supply enough fuel to the injectors.

A leaking fuel line can also be a reason your vehicle will not accelerate. A leaking fuel line will drain enough fuel to leave a shortage for the injectors (YourMechanic, n.d.). Speaking of leaks if your vehicle has a leak in the vacuum system, you may experience an issue with slow acceleration. Another thing to consider is the catalytic converter. If your catalytic converter is clogged or failing, it will prevent the proper amount of air from going into the engine. This can cause your vehicle to experience slow acceleration.

If you are experiencing an issue with your vehicle’s acceleration, these are things to consider having a mechanic investigate.


Autotechnician (2019). Top 6 Causes of a Car That Won’t Accelerate. Retrieved from https://cartreatments.com/car-wont-accelerate-symptoms-and-reasons/

YourMechanic (n.d.). Car is slow to accelerate Inspection Service. Retrieved from https://www.yourmechanic.com/services/car-is-slow-to-accelerate-inspection