What Causes No Injector Pulse? SOLVED!!!

What Causes No Injector Pulse

As we all know, for a car to operate stably, it needs 3 factors: fuel, compression, and spark. This rhythmic combination will help the engine start and perform smoothly. However, if one of the 3 parts has problems, it will significantly affect the quality of the engine. 

Then, the first detail that you need to consider checking is the injector pulse. The following article will give you an overview of the injector pulse and the cause of no injector pulse.

What Is An Injector Pulse?

The injector is an electronic control valve that specializes in providing fuel for cars. Specifically, it will inject energy directly to the engine’s cylinders with a certain pressure level. Fuel injectors directly affect the stable operation of the machine. Because if the injector fails, it will cause a lot

The injector works based on the PWM pulse mode controller. Specifically, the fuel injector will receive a signal from PWM to open the electromagnet and move the piston. From there, under the action of pressure, the fuel will escape in the form of tiny droplets. Normally, the amount of fuel injected is determined by the injector opening time or pulse width.

Currently, there are 3 variants of electronic fuel injection systems: MPI, GDI, and SPI. You need to have a good understanding of the electronic fuel injection system so that you can easily recognize when there is no injector pulse.

What Causes No Injector Pulse

Variants Of Electronic Fuel Injection System

SPI

SPI is also known as single-point injection. This is the first variant with a single injector located on the throttle body. No matter how many cylinders your car has, the engine will always have a port for refueling. The SPI setting is used during the transition from using the carburetor to the EFI system. Because the disadvantage of the carburetor is an irregular shape, the fuel is not distributed correctly to the MPI cylinders.

When the engine uses the EFI system, each cylinder will have a separate injector located near the intake valve’s position. That will help the ECU deliver the correct ideal air/fuel ratio to the cylinders.

GDI

Currently, the most modern injector is GDI – direct fuel injection. This design allows the fuel per cylinder next to the spark plug, contributing to faster fuel injection directly into the combustion chamber. From there, the engine’s performance will be higher and emissions will be significantly reduced.

To recognize when you need to have your injector system serviced again, you first need to learn about some of the leading causes of a no-injector pulse problem.

What Causes No Injector Pulse?

When fuel is injected, an air mixture is created inside the intake manifold. At the same time, the fuel injection sensor will work and send a signal to the ECU to provide the exact amount of fuel to be pumped. 

The camshaft sensor and the crankshaft sensor are the most important data that determine the accuracy of the output signal from the ECU to the injectors. Therefore, to check the injector, you need to check the voltage of the injector when the ignition is on. Then we can know why there is no injector pulse.

The nature of the cause of no injector pulse is that there is no power input. The three main factors that lead to that condition are blown injector fuse, bad injector electrical relay, and bad wiring.

Typically, fuses and relays will be located in the junction box in the engine compartment. When the fuse blows, the system will stop working, and the motor will stop running. 

The cause of the bridge failure can be a sudden change in voltage. Its consequence is that the electronic circuit will short circuit, the injector pulse will not appear.

If the fuse and relay are normal, you will need to check the cylinder without the injector pulse. 

Specifically, when you remove the injector and your engine restarts usually, the injector is undoubtedly having problems. It would help if you replaced it immediately.

Also, another way you can check and find out the cause of no injector pulse is to measure the resistance. This way, you will compare the resistor value with the highest and lowest. 

If the result is out of range, it means you need to replace the injector Because if you do not handle it in time, it will leave a lot of negative consequences; Typical is the reduction in engine power.

Please refer to the article “how to bypass reduced engine power” to understand more about engine capacity. 

Some Frequently Asked Questions

What controls the fuel injector pulse?

At present, the pulse injector operates based on the PWM pulse mode controller. Specifically, the fuel injector will receive a signal from PWM to open the electromagnet and move the piston. From there, under the action of pressure, the fuel will escape in the form of tiny drops.

How is no injector pulse diagnosed?

To diagnose no injector pulse, you can rely on one of the following 3 main causes: blown injector fuse, bad injector electrical relay, and bad wiring. That way, you’ll know why your car doesn’t have injector pulses.

What tells the injectors to fire?

When cold, the cooling sensor is a crucial element of the fuel mixture. When hot, the O2 sensor is the main factor affecting the air/fuel mixture. The crank sensor gives a signal about the exact moment to catch the spark plug.

Conclusion

Hopefully, the article will help you overview the injector system and the cause of the no injector pulse. You need to understand the following 3 main reasons: blown injector fuse, bad injector electrical relay, and bad wiring. 

That way, you will have a timely troubleshooting orientation that contributes to improving and ensuring the quality of your car’s engine. 

Hi! My name is Tom Watson– Founder of Garagefortress.com. I am happy to say that I am the owner of Garagefortress.com which is a website focused on automotive technology and cars...