What Are the Common Issues After Cleaning Fuel Injectors?

[StIsabella]

Common issues after cleaning fuel injectors include increased fuel consumption and higher idle speed. The working principle of fuel injector spraying is as follows: high-pressure fuel is pumped into the fuel injector supply port, creating high pressure inside the injector body that acts on the conical surface of the injector nozzle. When the fuel pressure exceeds the set value, the injector valve core opens, and high-pressure fuel is sprayed from the nozzle holes in a mist form into the engine cylinder for combustion, driving the piston's reciprocating motion. Common fuel injector faults and their solutions are: 1. Clogged nozzle holes: Use chromium oxide applied to a flat plate for grinding; if the cylindrical surface of the needle valve is significantly worn, it should be replaced promptly. 2. Poor sealing: Apply chromium oxide or toothpaste to the sealing band at the needle valve end. 3. Piston wear: Replace the piston.

[LeElle]

After cleaning the fuel injectors, my car developed a few minor issues. Initially, the idle was extremely unstable, with noticeable vibrations felt through the steering wheel, which lasted about three to four days before improving. Fuel consumption also increased slightly compared to before the cleaning, and the power delivery felt less smooth when driving. The most annoying issue was needing to start the engine twice during cold starts, whereas it used to start on the first try before. The mechanic explained that this was because the car's computer needed to readjust to the new fuel injection parameters and recommended driving more on highways to allow the system to relearn. However, I was advised to keep an eye on the sealing rings—last time, they forgot to replace them, which led to a slight oil leak at the connection point. Fortunately, it was discovered in time.

[McAdalynn]

There are several common situations to note after cleaning fuel injectors. Changes in fuel injection quantity may lead to poor adaptation by the vehicle's computer, manifesting as idle speed fluctuations and short-term fuel consumption increase. Improper operation may leave residual cleaning agent, causing difficulty in cold starts and requiring multiple ignition attempts. The most troublesome issue is with sealing rings, especially in older vehicles where rubber components have aged, making leaks prone to occur after cleaning. Additionally, some vehicle models may experience temporary illumination of the malfunction indicator light due to mismatched fuel injection data and oxygen sensor feedback. It is recommended to let the engine run continuously for 20 minutes after treatment to assist the system in resetting learning values.

[StFinn]

After cleaning the fuel injectors, I encountered a strange phenomenon in the first week: the engine intermittently jerked while waiting at a red light, causing the steering wheel to shake. The repair shop said this was a normal learning process and it would smooth out after driving a few dozen kilometers. However, starting the engine was indeed difficult, with one instance requiring three turns of the key before it fired up. The technician suggested that some cleaning agent might not have been fully purged and recommended revving the engine a few times while stationary. The most frustrating part was the fuel consumption, with the gauge showing an extra liter per 100 km compared to usual, which only returned to normal on the fifth day. As an aside, the sealing rings were checked, and the eight-year-old car did have minor seepage.