Multi-point fuel injection (MPFI) system
The main objective of the Multi-Point Fuel Injection (MPFI) system is to supply the correct ratio of petrol and air to the cylinders. What is the operation of cold start injector These systems work under two basic mechanisms
(i) Port injection
(ii) Throttle body injection
Port injection
In a port injection arrangement, the injector can placed on the side of the intake manifold near the port and the injector sprays gasoline into the air intake manifold. Gasoline mixes with air in a reasonably uniform manner. This mixture of petrol and air enters the cylinder through the intake valve.
- Injector
- Intake valve spark plug
- Port injection
- An injector is provided in the intake manifold of each cylinder. If there are six cylinders, there will be six injectors. Figure 9.4 shows a simplified view of a port or multi-point fuel injection (MPFI) system.
- Fuel injection
- Injector
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What is the operation of cold start injector
simplified diagram of a throttle body injection system (single point injection). This throttle body is similar to a carburetor throttle body in that the throttle valve controls the amount of air entering the intake manifold.
- Fuel injection
- Injector
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- Throttle body intake manifold
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An injector can mounted just above the throat of the throttle body. The injector sprays the gasoline into the intake manifold where it mixes with the air. What is the operation of cold start injector This mixture passes through the throttle valve and enters the intake manifold.
In a timing injection system, petrol will sprayed through the injector in one pulse. In continuous injection mode, petrol can continuously sprayed from the injector. Port injection systems and throttle-body injection systems can pulsed systems or continuous systems. In both systems, the amount of petrol injected depends on the engine speed and power requirement.
D-MPFI system
The D-MPFI system is a versatile fuel injection system. This way, vacuum sensed first in the intake manifold. Also, the volume of air can measured by its density. Figure 9.6 presents a block diagram of the operation of a D-MPFI system. When air enters the intake manifold, the manifold pressure sensor detects intake manifold vacuum and sends the information to the ECU.
The speed sensor sends information about the RPM of the engine to the ECU. The ECU sends commands to the injector to control the amount of petrol delivered to the injector. What is the operation of cold start injector When the injector sprays fuel into the intake manifold, gasoline mixes with air and the mixture enters the cylinder.
L-MPFI system
The L-MPFI system is a port fuel-injection system. This type of fuel quantity can controlled by engine speed and the amount of air actually entering the engine. This called air mass measurement or air flow measurement. A block diagram of the L-MPFI system When air enters the intake manifold, the air flow sensor measures the amount of air and sends the information to the ECU.
Similarly, the speed sensor sends information about the engine speed to the ECU. The ECU processes the received information and sends appropriate commands to the injector to regulate the amount of petrol supplied to the injector. When injection occurs, gasoline mixes with air and the mixture enters the cylinder.
Functional Divisions of the MPFI System
The MPFI system can functionally divided into
(i) electronic control system,
(ii) fuel system, and
(iii) air induction system.
These functional units can described in the following sections.
MPFI-Electronic Control System
The MPFI-electronic control system can shown as a block diagram. Sensors that monitor intake air temperature, oxygen, water temperature, starter signal and throttle position send signals to the ECU. What is the operation of cold start injector The air flow sensor sends a signal to the ECU about the amount of air intake.
The ECU processes all these signals and sends appropriate commands to the injectors to control the amount of fuel injected. When cold-start injector timing needed, the ECU activates the cold-start injector that can part of the fuel system.
cold start injector
A cold start injector can also known as a cold start valve and an important part of keeping your engine running smoothly. A cold start injector can a fuel injector that can electronically controlled and added to the cold air intake located in the intake manifold. If the engine temperature goes below a certain point, the system tells the injector to add more fuel to the air mixture. This helps to enrich the mixture in the cylinder and allows the vehicle to start easily.
Over time, as the vehicle can used every time it can started, the cold start injector will wear out and not function properly. When this happens, the engine will have trouble idling and sound rough. Additionally, every time you start the vehicle the engine stalls until it warms up.
One thing that can cause problems with cold start injectors is the hot start gap. If this interval can set too long, the car will crank for a long time before starting. If this happens, the thermometer start interval should can shortened. A cold start injector may can blocked by debris. When this happens, the vehicle will not start until the blockage can cleared. It starts the engine and then stops.
The opposite may also be true. If the cold start injector pressure is too low, air and fuel will mix and smoke from the engine, causing the car to stall when trying to start. This can a serious issue and cannot ignored, so contact a mechanic immediately to diagnose and/or replace the problem.
Since a cold start injector wears out over time, you should be aware of its symptoms before replacing it.
Signs that a cold start injector needs replacement
- The engine does not run when the foot can taken off the gas pedal
- The engine won’t start or stalls when you try to start it
- The engine floods when you try to start it
- Car won’t start
- If you experience any of the above symptoms, you should see a certified mechanic to fix your problem.
Bad or Failing Cold Start Injector
A cold start injector, also known as a cold start valve, an engine management component found in many road vehicles. Its purpose is to provide additional fuel to the engine to enrich the fuel mixture at colder temperatures where air density increases and additional fuel can required.
It plays an important role in the vehicle’s performance, fuel economy and starting characteristics, What is the operation of cold start injector so when a problem occurs, it affects the overall drivability of the vehicle. Typically a problematic cold start injector will exhibit certain symptoms that may alert the driver that a potential problem has occurred and may require repair.
- Rough start
One of the first symptoms usually associated with a bad cold start injector is trouble starting the vehicle. A cold start injector concentrates the vehicle’s fuel mixture during cold start or cold weather conditions. If a cold start injector fails or develops a problem, it may not be able to provide the extra fuel it needs in cold conditions, and the vehicle may have difficulty starting.
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MPG reduction
Low fuel efficiency is another sign of a worn or failed cold start injector. If the cold start leaks at the injector tip and allows fuel to can injected, it will cause an excessively rich mixture. This leakage can reduce fuel efficiency, and in some cases decrease performance and acceleration.
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- Engine performance problems
Engine performance problems can another symptom usually associated with a bad or failed cold start injector. A cold start injector that fails or leaks enough can cause engine performance problems. Leaking cold start injectors can reduce engine performance and acceleration resulting in a disturbed air fuel ratio. In more severe cases, a large amount of fuel leaks, causing the vehicle to stall or stall.
If your vehicle begins to display any of the above symptoms, or if you suspect that your cold start injector has failed, have the vehicle diagnosed by a professional technician, such as your mechanic, to determine if your car needs a cold start injector replacement.