What is a fuel injector, how to check or replace it

The fuel injector is mainly composed of a starting circuit, a cold fuel injector and a thermal time limit switch. The function of the cold start fuel injector is to inject fuel into the intake manifold when the engine is cold started to enrich the mixture and improve the engine. the cold start performance of the device. Cold-start injectors, also known as auxiliary injectors or cold-start electric valves, improve engine low-temperature starting performance. The advantages and disadvantages of the cold start injector are as follows: 1. Advantages: To a certain extent, it can improve the difficulty of cold start of the engine. 2. Disadvantages: Due to the cold start injector injecting fuel into the intake manifold, there is a disadvantage of uneven fuel supply for each cylinder.

The working principle of the fuel injector is: the high-pressure oil enters through the fuel supply port pump of the fuel injector, and the high pressure in the fuel injector acts on the cone surface of the fuel injection nozzle. When the oil pressure exceeds the set value, the valve core of the fuel injection nozzle opens, the high-pressure oil is sprayed from the small hole of the nozzle, and burns in the engine cylinder in the form of a mist, causing the piston to reciprocate."

Injector detection method:

1. Special equipment detection:

Just remove the injector and take it to the injector test bench for testing. If the detected injection pressure does not meet the corresponding technical standards, the atomization of the injector is not good, there is oil dripping or leakage, and the injector that cannot be restored after cleaning and adjustment must be replaced.

2. Detection on the engine:

The quality of the injector can be judged by the difficulty of starting the engine from cold and the color of the exhaust smoke after starting. It is difficult to start the engine cold, and the exhaust smoke after starting is white or black. If the fuel supply angle and cylinder pressure are normal, the injector and high-pressure fuel pump may fail.

Details of how to check a fuel injector:

1. Start the vehicle first and make the water temperature of the vehicle reach the normal range. On the premise of no fault code, increase the throttle appropriately, and the speed will quickly increase with the increase of the throttle. The sound of the engine is clear and powerful, which proves that the engine is in normal condition.

2. Test and start the engine on the engine, and pull out the injector harness connectors one by one. If the engine jitter increases, it means it is good.

3. Remove the injector mist for testing. Test the machine and check its fuel injection situation. If it does not inject fuel, it must be bad. If the atomization of the fuel injection is obviously poor, it means that it is also bad. If you want to be more professional, you must return the injector to inject fuel device manufacturer to analyze.

Steps to replace a fuel injector include removing and installing.

How to remove a fuel injector:

1. Loosen the fixing bolts, remove the steel plate and the fuel injection pipe oil seal.

2. Loosen the fuel injector holder and remove the fuel injection device.


How to install a fuel injector:

1. Install a new O-ring in the groove of the cylinder head and insert the fuel injection device.

NOTE: Coat the inside of the O-ring with oil and take care that the O-ring does not get caught.

2. Install the nozzle holder and temporarily install the fuel injection device.

NOTE: Do not secure the nozzle holder.

3. Put the new fuel injection pipe oil seal on the fuel injection device, and then install the steel plate.

Note: Do not use too much force when installing the fuel injection pipe oil seal on the oil nozzle. If the position of the oil seal and the oil nozzle is deviated, it may cause oil leakage or poor assembly of the fuel injection pipe.

4. Temporarily install the fuel injection pipe, and then tighten the fixing bolts of the nozzle holder. Tightening torque: 25N.m.

5. Write the fuel injection device correction value into the engine ECU.

You may be wondering how to keep your fuel injector in a good condition. Here are some useful tips offered by Vigers:

1． Remove carbon deposits. Injector carbon deposits are not only easy to block the nozzle holes, but also overheat the fuel injection nozzles. Therefore, the carbon deposits must be removed during maintenance, repair and repair. To remove carbon deposits, emery cloth and steel scraper should not be used, but wooden, bamboo or aluminum scrapers can be used. In order to remove the dirt and carbon deposits in the oil inlet channel and the hole, the injector can be soaked in kerosene or light diesel oil for several hours, and then removed with fine copper wire. The carbon deposits on the oil needle or the oil injection hole body are removed by rubbing the parts back and forth on the cork board. Parts with carbon deposits removed must be cleaned with gasoline or kerosene.

2. The fuel injection hole is blocked by carbon deposits, which can be carefully cleaned with copper wire or steel needle smaller than the injection hole, and blown clean with compressed air.

3. If the sealing between the oil needle and the nozzle is not good, you can clamp the oil needle on the electric drill, dip a little abrasive paste (chromium oxide and oil) on the tip, hold the nozzle by hand and put it on the oil needle, start the electric drill, and grind for a few seconds. The ground parts should be smooth, free of wear marks and deflection, and then carefully cleaned and reassembled for testing.

Beijing Vigers Co., Ltd. is a leading manufacturer specializing in machinery parts including Fuel Injector, Injector Nozzles, Valve Assembly, Fuel Injection Pump, and Machinery Parts. For wholesale you can always rely on Vigers’strong technical strength, professional design and production team.
Website：https://www.bjvigersinjector.com/en-US/