Common Reasons for Acceleration Stumble in a Mini From Experts in Louisville
Posted on October 15, 2021 by smikyautomowp
Driving a MINI is about enjoying the journey, not just the destination. MINIs are known for their customizable exteriors, compact style, and quick acceleration. People buy MINIs because they are fun to drive.
When something goes wrong with the acceleration of the MINI, the fun stops. If your vehicle is hesitating or stumbling when trying to accelerate, it is best to take it to a technician sooner rather than later. Prolonging service to your vehicle could lead to more serious problems within the engine.
The area of the engine that commonly has a negative impact on acceleration is where the fuel and oxygen are regulated. The engine needs the air and fuel to be combined in a way that powers the engine. If dirt, debris, damage, or wear of the parts within this system causes an incorrect blend of fuel to oxygen, the vehicle cannot produce enough power to accelerate smoothly and quickly.
The parts of the fuel-oxygen system that are commonly replaced when the vehicle hesitates or stumbles when accelerating are:
- Fuel Injector: Simply put, the fuel injector sprays the fuel into the engine. There is usually 1 fuel injector per cylinder in the engine. If a vehicle has 6 cylinders, then it has 6 fuel injectors. An 8 cylinder vehicle has 8 fuel injectors. Fuel injectors can become clogged from debris, corrosion, or from using a lower grade gas. It is recommended to use premium gas in your MINI for best performance.
- Mass Air Flow Sensor: The mass air flow sensor, or MAF sensor, determines the amount of oxygen needed in the engine to combine with the fuel. Dirt and debris can accumulate on the sensor preventing it from calculating the proper amount of fuel to oxygen ratio. If not serviced quickly, this can cause the vehicle to stall when starting.
- Throttle Position Sensor: The throttle position sensor, or TPS, monitors the position of the gas pedal and determines how much air is needed in the engine. When you press on the gas pedal, the throttle body is opened to allow air to flow to the engine. The sensor collects this information to help regulate the necessary amount of air flow inside the engine. Dirt and grime can cause the sensor to inaccurately calculate how much air is needed to combine with the fuel for the engine to accelerate smoothly.
Other parts within the engine that can lead to acceleration stumble or hesitancy are:
- Dirty air/fuel filter: Clogged air and fuel filters prevent the necessary amount of air and fuel to pass through the filter decreasing engine performance. These parts are typically checked as part of an oil change, so if the air or fuel filter is dirty it can be caught before further damage occurs.
- Damaged Connector: The connector is where the electrical wires from one part of the engine connect to another part of the engine. If the wires are damaged or loose, the lack of electrical current can cause acceleration stumble. Think of it like plugging an appliance into a loose fitting wall outlet. Without the proper connection, the appliance won’t work properly. The same applies to the connector.
- Air Intake System: The air intake system draws air through a hose, near the front end of the vehicle, into the air filter, and into the engine to combine with the fuel. If the system is clogged, not enough air is allowed to pass through the hose or filter, decreasing what can be combined with the fuel, leading to acceleration stumbling.

St. Matthews Imports Experts in MINI Service
At St. Matthews Imports, we pride ourselves on being a family-owned and operated service center for the past 50 years. Our Hubbards Lane location, in Louisville, is the largest independent shop in the area for automotive service and repair. We are rated Louisville’s #1 Import auto repair shop, have an A+ rating with the Better Business Bureau, and are recognized as a Leo Readers’ Choice Winner.
Our ASE Certified Technicians specialize in Asian, Domestic, and European auto repair. Our technicians use factory-grade tools and OEM parts in our state-of-the-art facility to make sure your vehicle gets back on the road running like new.
Give us a call at (502) 896-0305 to speak to an expert technician for answers to your questions or to schedule an appointment. We also offer convenient appointment scheduling on our website.
* Mini Cooper Car image credit goes to: bruev.