Car won't accelerate - Causes and Mitigation

Acceleration-related problems may be difficult to identify when driving on even terrain or in high-traffic locations. The driver notices that the car won’t accelerate when they move from flat roads to steep or hilly roads. The problem also manifests when moving in a low-traffic zone. What causes these problems? Are there remedies for these problems? Let us look at the popular things that cause the car not to accelerate.

Faulty mass airflow sensor

The mass airflow sensor controls the quantity of air that gets into the cylinder for optimum fuel combustion. The sensor should be kept. Slight clogging impedes its performance. A clogged MAF cannot send accurate data to the electronic control unit. The MAF data is vital for calculating air-fuel ratios to match the acceleration needs. Expect sluggish acceleration if the mass airflow sensor is clogged or dirty. The air supply is insufficient to facilitate maximum fuel combustion.

Malfunctioned oxygen sensor

The car won’t accelerate if you are driving around with a bad oxygen sensor. It is a device that monitors the quality of exhaust gases and sends data to the ECU to adjust air-fuel intakes. The sensor needs to be in good health if the driver is to enjoy a smooth and predictable acceleration.

Subsequent air-fuel intake relies on the real-time data supplied by the sensor. Once the sensor gets damaged, it becomes impossible for the ECU to acquire the data. It causes delayed acceleration irrespective of the position of the acceleration pedal.

Dirty fuel filter

A clogged fuel filter implies that the amount of fuel intake is uneven. In one instance, there is enough fuel in the cylinder. In another, the amount of fuel is insufficient. When the fuel filter is clogged, the driver experiences slow responsiveness to acceleration and, in some cases, a total loss of engine power. The solution to this is replacing the fuel filter.

Damaged TPS

The throttle position sensor identifies the real-time angle of the throttle valve. The opening angle depends on the position of the acceleration pedal. When the TPS is faulty, it becomes difficult to control the engine speed using the acceleration pedal. The engine raises or lowers its speed without the intervention of the accelerator pedal.

Dirty air filter

Each combustion stroke requires a rich supply of fresh air. The air filter removes dirt from atmospheric air before sending it to the combustion chamber. Using the same filter for a long time causes it to clog. That leaves little space for passing a fresh supply of air and impedes the quality of acceleration.

Bad timing belt

The deviation of the timing belt by a slight margin deals a blow to the quality of acceleration.

The car won’t accelerate if there is a problem with its transmission system. It could be a slipping clutch or any other faulty component.


Several issues can cause the car to have acceleration problems. They range from malfunctioned sensors and poor air-fuel mixtures to more complex matters like bad timing belts and faulty transmission system components. Visit a repair shop when these symptoms occur.