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BMW 740il Fuel Injector

Finding the Reasons why a BMW 740il Fuel Injector Fails

Modern cars like the BMW 740il use fuel injection technology in delivering air-fuel mixture to the engine. Through this device, the engine can burn fuel faster and more efficiently. As a result, the car gains more horsepower and torque. There's no doubt that the ultimate goal of a fuel injector is to enhance the overall performance of your vehicle. However, a few issues may arise at times that would affect your car in a very bad way. To diagnose injector-related problems, you need to be familiar with the following steps. These will help you determine the right course of action to take in order to restore your car's normal operation.

Fuel restriction

Fuel restriction is the culprit behind the poor performance of your engine. This happens when the valve of the fuel injector does not open or close the way it has to be. A faulty injector usually sends the wrong information to the car's ECU. This problem results in either excessive or inadequate amount of fuel delivered in the engine. To diagnose this probblem, check the BMW 740il fuel injector for clogs. A congested injector won't function normally. Try cleaning the injector first and see if you can restore it in good condition. Replace it if the problem still persists.

"Check Engine" light is on

This warning light is usually activated when there is a lean misfire. A misfire occurs when there's a huge amount of unburned fuel in the car's cylinders even after you shut the engine off. The oxygen sensor detects it as fuel waiting to be delivered into the engine. Because of this error in reading, the fuel injector remains open for a long time. The cylinders then receive uncontrollable amount of air-fuel mixture, which is very damaging to the car's combustion system. When this happens, you must perform a test using an automotive scan. Plug it while the engine is off. Observe the readings and wait for the code that points to fuel injector problems.


A leaky fuel injector causes the engine to overheat fast. Cracks and holes on the injector allow unburned fuel to spill out and spread to the other components of the combustion system. Worse, it can damage the catalytic converter severely. To inspect for leaks, simply touch the engine parts nearby the fuel injector especially the cylinders. If you notice a lot of oil deposits, replace the injector ASAP to avoid further damage.

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  • How to Clean a BMW 740il Fuel Injector

    The BMW 740il fuel injector is always prone to clog and dirt.You must take good care of it, because injector contaminants are very difficult to remove. They can form a wax-like substance that sticks to the inner linings of the injector lines. To eliminate these harmful debris, here are the following tried and tested cleaning tips that you can follow:

    Cleaning tips

    • Stay extra cautious during the cleaning process.
    • Cleaning the fuel injection system entails a lot of risk, because you have to do it while the engine is running. Gasoline and cleaning solvent are flammable materials. That's why you have to park the car inside the garage to keep it out of direct sunlight. Always have a fire extinguisher ready in case of fire.

    • Know the right type of cleaners to use.
    • Not all fuel injector cleaners are manufactured under the same chemical formula. You have to find the cleaner that is suitable to a BMW 740il. Avoid using heavy solvents because they can cause the rubber seals and the plastic fuel pump hoses to deteriorate.

    • Make sure there's enough fuel in the tank.
    • Do not pour the injector cleaner into a reservoir when there's inadequate amount of fuel in it. The cleaner can dissolve the sediments at the bottom of the tank, which may clog the injectors.

    • Clean the fuel injectors regularly.
    • Don't wait for the signs and symptoms of injector failure to manifest before you start cleaning. Remind yourself to unclog your fuel injectors after driving 25,000 to 30,000 miles. When there's heavy dirt build up, pour two bottles of cleaner into the tank to flush out all clogs.

    Other preventative measures

    • Use high-quality petroleum.
    • Some car owners, just to save up a few pennies, choose to buy poor-quality, untreated fuel. This type of fuel usually costs less because it did not undergo refinements. Beware of this product because it contains more contaminants that may clog your fuel injectors.

    • Replace your car's fuel and air filter regularly.
    • The filters in your BMW 740il are the first line of defense against contamination. That's why it is necessary to change them regularly to ensure their optimum performance.