Injector Cleaning and Testing on a BMW 118i direct injection
What are fuel injectors?
The fuel injector is an electronically controlled valve that is supplied with pressurized fuel by the fuel pump and when energized atomizes the fuel into a fine mist so that it can burn easily in the vehicle’s engine.
How do we know the fuel injectors need cleaning?
- Engine stuttering
- Loss of performance
- Rough idling
- Engine stalling
Easiest Method to clean Injectors:
Pouring fuel injector cleaners into the tank is a safe, time saving method to try. But if that doesn’t solve the problem, nothing beats a proper injector cleaning.
Thorough and Professional Method to deep clean and test Injectors:
This is where Squad Workshop’s professional tools come in handy. First step is to remove the fuel injectors from the engine which can be a labour intensive job if we also have to remove the intake manifold.
The injectors are first visually inspected for damages, followed by electrical resistance check.
The exterior is then cleaned thoroughly to remove any dirt, grease or other foreign matter that will contaminate the cleaning and flow testing solutions. They are then mounted to the flow tester, where they will be tested at various pressures (to simulate idling, normal acceleration and full-throttle) and the spray patterns checked.
The results are recorded to ensure that the cleaning process will produce 4 injectors that work identically, for the best performance possible. The cleaning process begins with the injectors being a placed in the ultrasonic cleaning tank.
They are connected to a power source pulse them on and off during this operation, this ensure that the internal components (such as the valve and the actuator) are thoroughly cleaned.
The injectors are then remounted onto the flow testing bench, and the second results are recorded for comparison to the first results. If any of the injectors do not flow as expected, all four will be cleaned again in the tank and retested.
This process is the most effective cleaning method and produces measurable results to guarantee success. The only nuisance? Having to relinquish your vehicle for some time, but the results speak for themselves, smoother idling, better throttle response and reassurance that the fuel injectors lifespan are increased. Clean injectors will aid in achieving good fuel consumption and protect the engine from damage from overly lean burn.
Cleaning is more economical as a fuel injector can be costly to replace. This process is highly recommended to be carried out as a periodic maintenance process at 40k-60k intervals.
In the following example, we have injector testing for a BMW 118i direct injection. Results: Spray pattern on new injector is finer and downward. Whereas spray pattern on old injector is feathering at top of spray. The amount collected after test is also more for the old injectors meaning more fuel is used when driven, causing poor fuel economy.
This customer has hence decided to replace all injectors and reported an improved fuel consumption.