What You Need to Know about Fuel Injector

1. Introduction

There is a situation. The fuel injector is mounted on the original carburetor position and combined with the throttle. This refers to the single-point electronically controlled fuel injection.

The advantages are low cost and simple maintenance. The disadvantages are the unequal distances between the injection point and each cylinder as well as unequal fuel distribution. Fuel is prone to adhere to the intake pipe wall during the cold start.

If the fuel injector installs on the intake pipe of each cylinder, this refers to a multi-point electronically controlled fuel injection device.

The advantage is that each cylinder has its own injector, and the injector is as close as possible to the intake valve. It avoids the disadvantages of single-point electronically controlled fuel injection. The disadvantage is the high cost and complicated maintenance.

Most modern vehicle engines use the multi-point type. There are also a few economy cars using the single-point type. The single-point type is a must if the old carburetor engine converts to the EFI system.

2. Working principle

The fuel injector is controlled by the solenoid coil. The on/off of the solenoid current is controlled by the ECU. It receives a feedback signal from the sensor and sends an electrical signal to the injector. As a result, the injection time can be determined. This time interval is called the "pulse width" of the injector.

The injector solenoid coil is energized to produce a magnetic field. The plunger is sucked up under the action of the magnetic field to overcome the spring force. It leaves the valve seat with the valve. The gasoline is sprayed out from the nozzle under pressure.

When the magnetic field disappears as the solenoid coil is disconnected, the plunger moves down under the action of spring force. The valve body closes the nozzle against the valve seat. Then, the gasoline cannot come out.

The valve is divided into two types: ball valve and needle valve by construction. In order to ensure the accuracy of fuel injection, both valves and the valve seat require high machining accuracy. The lift of the valve body is tiny, only about 0.1 mm.

The high-pressure fuel pipe is in front of the injector due to the pressure regulator. There is a low pressure of the intake manifold behind. The pressure difference forms a negative pressure. The fuel is formed into a mist spray to the intake valve.

3. Inspection

When the engine is running, use a long-handled screwdriver or stethoscope to listen to the injector whether there is a "tada, tada" sound.

If it is not easy to judge because of other noise, you can unplug and then plug the injector harness to identify whether it works during the listening.

If the injector does not work, connect the test light to the injector harness plug and start the engine. If the test light flashes, the injector control system works normally. The issue is in the fuel injector.

Measure the resistance of the solenoid coil with the multimeter. If the value is normal, the injector blockage (by the combustion of carbon and fuel gum. This is the most common reason). The fuel injector should be cleaned or replaced. If the resistance is abnormal, the injector must be replaced.

The injector control system or circuit is faulty if the test light does not stay on. You should first check whether the injector-related circuit is good. In the case of ensuring that the external circuit is well, it can be judged to have problems in the computer.

4. Maintenance

The fuel injector should be checked for every 700h of working. If the opening pressure is lower than the specified value, or there are too many carbon deposits on the needle valve head, the needle valve should be put into clean diesel fuel to get rid of the carbon. Unclog the spray hole with a fine steel wire.

After all these things have been done, install the needle valve and check again. The cylinder injection pressure difference must be less than 1 Mpa.

Check the fuel supply time of the fuel pump regularly. If the time is too early, the vehicle will be hard to start. If the time is too late, it will lead to black smoke from the exhaust, high engine temperature and increasing fuel consumption.

The injector needle valve has high precision. The spray hole aperture is very small. Therefore, don't overlook the choice of diesel fuel. Otherwise, the fuel injector can not work properly.

When replacing the injector needle valve, the new component should be soaked in hot diesel fuel at 80°C for about 10s to fully dissolve the anti-rust oil. Then move the needle valve back and forth in the valve body to wash off.

This avoids the failure of sticking to the needle valve when the injector is working due to the dissolution of anti-rust oil.

When the fuel pump is working properly, check the injector. Start the engine and touch the injector with a stethoscope to listen to the sound. If there is no sound, the injector does not work.

Connect a large impedance test light to the injector harness plug. Start the engine. If the test light stays on, the injector control circuit is normal. The issue is in the injector. If the test light fails, the problem is in the injector control circuit.

5. Reasons for Choosing Delcoribo Fuel Injectors

Vehicles need correct fuel injection to satisfy both fuel system and ignition system. The fuel injector takes charge of this vital injection. We try our best to provide superior products to customers. It needs everything right to get proper air-fuel mixture. You can always trust our components.

When we are talking about cars, fuel economy is what we care about. Delcoribo fuel injectors take advanced technology to get optimum fuel economy and low emissions. We have special design to increase the anti-clogging. Drive at high speed from time to time, slight impurities will be sprayed.

Fine parts go along with impeccable service. We welcome all demands and suggestions before and after your purchasing. Products will be delivered on time. Get real good fuel injectors to control fuel injection.