The hesitation when accelerating is most likely due to a dirty fuel injector. Fuel injectors may become dirty over time and not be able to provide as much fuel to the cylinder as is needed. Dirty fuel injectors may cause the engine to run lean which will in turn, cause hesitation when accelerating.
I would recommend having a certified mechanic, such as one from YourMechanic, come and inspect your vehicle’s hesitation issue and perform a fuel injection service. This service will be very helpful in determining the cause of your vehicle’s hesitation issue.
Mini Cooper Jerky Acceleration
It could be that your fuel injectors may have become dirty over time and not be able to provide as much fuel to the cylinder as is needed.
Why do I feel like my Mini Cooper is running rough? How can I fix it? What Remedy can I use?
To start with you can try a fuel injector cleaner or use some Techron concentrate plus added to the fuel tank at your next fill up.
If this does not help then you will probably need to have the fuel system cleaned using a machine such as BG Fuel/Air Induction Service machine. This machine uses high pressure and a special cleaning solution that cleans out all of the passages in the fuel injectors and intake manifold. If this is done it should get rid of the hesitation problem.
If the fuel injectors become dirty, they will not be able to provide as much fuel to the cylinder as is needed. Dirty fuel injectors may cause the engine to run lean which will in turn, cause hesitation when accelerating.
A plugged catalytic converter can also cause hesitation when accelerating. The catalytic converter changes un-burnt hydrocarbons and carbon monoxide into water vapor and carbon dioxide. If the cat is plugged it will restrict the amount of exhaust gas that can flow out of the engine. This will cause a restriction in air flow which will in turn, cause hesitation when accelerating.
It’s also possible that low oil pressure or low compression could cause hesitation when accelerating. I would recommend checking the oil level to make sure it is full, and if so, you may want to have a certified mechanic check for low oil pressure or low compression as these can be caused by numerous problems.
There are many reasons why a vehicle might hesitate when accelerating, but most of them fall into three areas: spark, fuel or compression. As the vehicle is accelerating, it is demanding more fuel and air from the engine. If something prevents the engine from providing this additional amount, the driver will perceive a hesitation in acceleration.
The following are some of the most common causes of hesitations during acceleration:
Dirty Fuel Injectors
One of the most common causes of hesitation when accelerating is dirty fuel injectors. Over time, fuel injectors develop deposits on their tips that inhibit their ability to spray properly. This results in uneven distribution of fuel between cylinders, which can cause hesitation during acceleration. The best way to clean a set of injectors is to use a commercial cleaning solution that’s added to the gas tank. These solutions will remove carbon deposits and other debris within a few hundred miles of regular driving. These cleaning solutions are not expensive and are available at any auto parts store.
How do you test a MAF sensor on a Mini Cooper?
In virtually all vehicles made since the early 1990s, a mass air flow sensor provides feedback about how much air is entering the engine so that the computer can make adjustments to keep the car running optimally. If this sensor becomes dirty or
A lean mixture is when the fuel injectors are not delivering enough fuel to the engine to run correctly. The Mini Cooper has a light that will come on if the car is running lean, which means that there is too much air in the fuel mixture. This problem may be caused by a faulty O2 sensor that is not detecting the amount of oxygen in the exhaust system and causing too much air to enter into the engine. Another possible cause is leaky gaskets or valves that are allowing exhaust gases to get back into the cylinders, which would also make the engine run lean.
A mass airflow sensor measures how much air is entering into the intake manifold and tells your cars computer how much fuel to add to the engine for optimal performance. A faulty mass airflow sensor will cause your car to run rich or lean since it will not be able to accurately measure how much air is coming into the motor.
The first thing you should do when your car starts having throttle response problems is check for any trouble codes using an OBD-II scanner like the ones found on eBay for less than twenty dollars. If no trouble codes are present, then you can test the throttle position sensor with a voltmeter or multimeter to make sure it is sending proper signals to your cars computer.
There are many reasons why your Mini may hesitate when you try to accelerate, but sometimes this hesitation is caused by something that we can take care of by our selves – a dirty MAF (Mass Air Flow) sensor. A dirty MAF sensor will often cause the engine to hesitate or stumble during acceleration, especially during cold starts. The symptoms of a bad MAF sensor are almost identical to those of a bad oxygen sensor or a vacuum leak. Because the MAF sensor is just one component in the system, it might not be easy to find it really faulty. This happens because the other parts in the system can also cause similar problems as those caused by a bad MAF sensor.
The good news is that cleaning a MAF sensor is easy and only takes about 20 minutes and some electrical cleaner spray from your local auto parts store.
You may have an issue with low fuel pressure. The first thing I would do is put some fuel injector cleaner in a full tank of gas to see if that helps. If the problem still persists, you should have the fuel pressure checked. If the fuel pressure is low, you may have a faulty fuel pump or a clogged fuel filter.
If the fuel pressure checks out ok, then you may have a dirty throttle body or Map sensor. You need to remove the air intake hose between the air filter box and the throttle body. Spray some throttle body cleaner into the throttle body while pressing on the accelerator pedal several times. This will help clean out any carbon build up in there. Make sure you start and run the engine after doing this so it can idle for at least 5 minutes before driving again. Also make sure you spray some throttle body cleaner around all of the gaskets as well as inside and outside of them to help keep them from sticking together when putting everything back together.