Case Study: Solving a Misfire Problem in an MG HS / ZS
Assalamu Alaikum, readers of The Auto Pulse! Today, we're tackling a very common issue that we're seeing more frequently in modern cars: engine misfires. The vehicle in our workshop is an MG, and the owner complained of rough running and a "misfiring" sensation while driving.
Our initial scan confirmed the issue: the car was logging codes for a "random cylinder misfire." This often points to a fuel delivery problem. Our prime suspects were the fuel injectors, so we removed them for testing. Watch our full diagnostic video below to see the process in action.
Step 1: Physical Inspection and Initial Testing
Visually, all the fuel injectors appeared to be in good condition with no obvious damage. However, a physical inspection can't reveal internal clogs. To find the real problem, we placed them on our specialized fuel injector testing machine.
The Problem Revealed: Spray Pattern and Flow Test
The machine allows us to check the fuel spray quality (atomization) and measure the flow rate. During the test, we immediately found the culprit. While three injectors sprayed a fine, continuous mist, Injector #2 was visibly hesitating and stuttering. It would pause mid-spray, failing to deliver a consistent stream of fuel. This "sticking" injector was undoubtedly causing the random misfire.
The Solution: Ultrasonic Injector Cleaning
Instead of immediately replacing the faulty injector, which can be expensive, we performed an ultrasonic cleaning service. The machine uses high-frequency vibrations and a special cleaning fluid to break down stubborn carbon deposits inside the injector.
The Successful Result
After the cleaning cycle, we re-tested the injectors. The results were perfect:
- Injector #2 was no longer sticking and delivered a perfect, continuous spray.
- In the final flow test, all four injectors delivered an identical quantity of fuel (60 mL).
This service saved the customer the cost of a new injector and completely resolved the engine's misfire. If you are experiencing similar issues with your MG or any modern GDI vehicle, we highly recommend getting your injectors professionally cleaned and tested.
Thank you for reading, and Allah Hafiz.