kumar abhishek

• Mar 26th, 2007

 

mpfi is multi fuel injection system.it controls the timing and amount of fuel injected.it is of 2 types - d-mpfi and l-mpfi.in d-mpfi the air is first sucked into the intake mainfold cylinder which the sends information to the ecu(electronis control unit) and the rpm sensor connected with engine also sends information to ecu in return ecu will send information to injector to inject the required amount of gasoline into the pipe connected to engine .through this pipe the correct ratio of air -fuel mixture enters into the cylinder.

anoop4real

 Profile Answers by anoop4real Questions by anoop4real

• Mar 27th, 2007

 

Hi,
Thanks for the information.So does the engine require a spark plug? or It works like an S.I. engine. Can you point me some pdfs regarding mpfi?

Regards
Anoop

vijay4umech

 Profile Answers by vijay4umech 

• Jul 28th, 2008

 

It is multipoint fuel injection system in which the air and the fuel is mixed just before the inlet. these it will not for one cylinder engine it is the system used to inject fuel mixture to many cylinder equally it has a common center from which the air comes in and mixes with the fuel and finally it is injected into the cylinders.

sandesh bhat

• Jul 15th, 2011

 

ecu does not sends the information.it transmits the voltage or amount of current to particular operating system, which operates only with that particular amount of current.that supply of current depends upon the thickness of wire,then coils,circuits which they control,simply that increases or decreases the amount of current.
MPFI system injectors are fitted inside the intake manifold before the valve intake valve. the air fuel mixing take place when injector injects gasoline which mixes with air in that time valve starts to open,so the mixing take place also in the inside the cylinder.

Bhushan Kulkarni

 Profile Answers by Bhushan Kulkarni Questions by Bhushan Kulkarni

• Aug 10th, 2011

 

anoop,now we are using this technology in four wheelers(cars) it doesn't require spark plug & it does not work like S.I. but like C.I.(compression ignition).

rohan tiwrekar

• Oct 16th, 2011

 

we require spark plug in mpfi engine as the technology is just to produce proper air fuel mixture but the operation of si engine remains same also ecu even controls spars advancing

T240GUY

• May 20th, 2012

 

Basically, a multi-point fuel injection system or MPI puts a fuel injector in the intake plenum directly over each intake port in the head. The ECU reads RPM, engine load, throttle position, and crankshaft position sensor to individually control each fuel injector.

Sequential fuel injection, reads the same sensors. The only difference is, MPI manages and controls each injector independently and SFI takes readings and applies them to all injectors as a whole. For instance, under certain conditions, and SFI system takes readings from the sensors.

It then sees that it needs 110 cfm of fuel for a particular cylinder, it then feeds 110 cfm to all injectors. On MPI system, one cylinder might need 110 cfm, while another 112 cfm, and another 118 cfm. The MPI is able to adjust each injector independently so each cylinder only receives the exact amount of fuel required.

So in conclusion, the MPI is more fuel efficient and more precise in metering fuel to the cylinders. The SFI is essentially a Throttle body injection system, with the injectors mounted at the intake ports instead of the intake plenum

N.j

• Sep 14th, 2012

 

can anybody describe mpfi system for s.i engines?

bijoy kumar pradhan

• Sep 15th, 2012

 

how to use gear box in compressor

bhanu tomar

 Profile Answers by bhanu tomar 

• Oct 6th, 2012

 

MPFI means multi-point fuel injector. Latest 4 stroke and 4 cylinder engines consists of MPFI system which enables them to inject fuel at each cylinder at a single time.

Sanjay

• Sep 10th, 2016

 

We will be familiar with the words MPFI and CRDI in the advertisement of some vehicles. But we will not be aware about these terminologies. The MPFI is otherwise known as the Multi point fuel injection engine. The MPFI engine got this name because of the reason that each cylinder is having a fuel injector installed near them. This article mainly deals with the working of a MPFI engine and its advantages.

What is MPFI?
We will be familiar with the words MPFI and CRDI in the advertisement of some vehicles. But how many of us know what MPFI exactly is? The term MPFI is generally used to specify an engine variant used in the petrol vehicles. A small computerized system is used to control the engine of the car. A petrol car will have more than three fuel burning chambers or simply cylinders. The MPFI engine is abbreviated as the Multi point fuel injection engine. The MPFI engine got this name because of the reason that each cylinder is having a fuel injector installed near them. That is why they are called as the Multi point fuel injection engine.

Principle behind MPFI
The power is produced in a petrol engine is by burning the fuel. In petrol engine, the petrol is ignited. At first, the petrol is allowed to mix with air. It is then ignited in a cylinder called as the combustion chamber. This combustion of the petrol produces a sufficient energy to run the engine. The Carburetor is being used in the earlier days before the invention of MPFI engine. It is the duty of the carburetor to mix the fuel and air in a fixed air-fuel ratio. The fuel thus mixed in the carburetor is then given to the combustion chamber where this mixture gets ignited. The power thus obtained from the ignition of gas is used to drive the engine. The main disadvantage of the Carburetor is that the mixing of fuel and air is not in the proper ratio which leads to the wastage of fuel and the pollution is high. Since the emission rate is high in carburetor engine, the MPFI engine is being introduced.

Working of MPFI engine
The MPFI is an advanced version of carburetor engine. As we said earlier that the MPFI engine is having a fuel injector for each cylinder. A computer is used to control each and every fuel injector individually. The computerized system of the car consists of a microcontroller. This microcontroller monitors each fuel injectors and keeps on telling each injector about the amount of fuel to be injected to the cylinder so that the fuel wastage can be reduced. Since there is a controlled fuel usage, the engine is known for its fuel efficiency.

Even though the working of MPFI engine is somewhat similar to the carburetor engine, each cylinder is treated individually. An input is fed to the computerized system in order to calculate the amount of air and fuel is to be mixed and send to the combustion chamber. A several stages of calculations are to be made in order to judge the right amount of fuel to be mixed. After this calculation, the proper fuel is delivered at the proper instance.

There are a number of sensors used in the MPFI engine. At the time when the inputs are given to the cars computer, it begins to read the given sensors. The things which can be known from the sensors are listed below:
The engine temperature of the vehicle.
The speed at which the engine is running.
The engine load.
The position of the accelerator.
The cylinders air-fuel pressure.
The rate of exhaust.

The amount of fuel to be injected into the combustion chamber is decided by analyzing the inputs given to the computerized system of the MPFI engine. In modern MPFI engines, a memory unit is additionally installed. This will make the MPFI engine capable of storing the user settings so that it can operate easily. The driving habits of a driver can also be detected by this system so that the MPFI system itself can change the predefined settings which suit the user. There are namely two types of MPFI engines namely:
Sequential
Simultaneous
Thus it can be noted that the cars of today are truly intelligent.

Advantages of MPFI
The advantages of MPFI engine are as follows:
Each cylinder or the air-fuel mixing chamber is supplied with the precise and uniform quantity of the air-fuel mixture.
Engine crank is not necessary in cold climatic conditions.
Good engine response to the throttle applied.
Accurate supply of the air-fuel mixture.
ECM technique is used to control the engine.
High fuel efficiency or mileage.

Sanjay punia