The Electronic Fuel Injection System Engineering Essay

The Electronic Fuel Introduction plan can be separated into three: basic sub -systems. These are the fuel donation plan, courage collation plan, and the electronic administer plan.

The fuel donation plan consists of the fuel tank, fuel cross-examine, fuel distil, fuel donation pipe (fuel reprove), fuel injector, fuel constraining chairman, and fuel requite pipe.

Fuel is pronounceed from the tank to the injector by media of an electric fuel cross-examine. The cross-examine is typically located in or close the fuel tank. Contaminants are distiled quenched by a haughty calibre in course fuel distil.

Fuel is oceantained at a steady constraining by media of a fuel constraining chairman. Any fuel which is referable attributable attributable attributable pronounceed to the ingrasp varied by the injector is requiteed to the tank through a fuel requite pipe.

The Courage Collation Plan

The courage collation plan consists of the courage cleaner, courage issue meter, extinguish valve, courage ingrasp lodging, ingrasp varied runner, and ingrasp valve.

When the extinguish valve is unreserveded, courage issues through the courage cleaner, through the courage issue meter (on L expression plans), spent the extinguish valve, and through a courteous tuned ingrasp varied runner to the ingrasp valve.

Courage pronounceed to the engine is a influence of driver insist. As the extinguish valve is unreserveded aid, over courage is undisputed to invade the engine cylinders.

Mostly the L expression EFI plan estimates courage issue instantly by using an courage issue meter. The D expression EFI plan estimates courage issue ininstantly by monitoring the constraining in the ingrasp varied.

Electronic Administer Plan

The electronic administer plan consists of diverse engine sensors, Electronic Administer Individual (ECU), fuel injector assemblies, and akin wiring.

The ECU designates nicely how considerable fuel needs to be pronounceed by the injector by monitoring the engine sensors.

The ECU turns the injectors on ce a nice total of date, referruddy to as introduction pulse width or introduction space, to pronounce the peculiar courage/fuel pertinency to the engine.

Basic Plan Agency

Courage invades the engine through the courage collation plan where it is estimated by the courage issue meter. As the courage issues into the cylinder, fuel is qualified into the courage by the fuel injector.

Fuel injectors are finished in the ingrasp varied rearwards each ingrasp valve. The injectors are electrical solenoids which are operated by the ECU.

The ECU pulses the injector by switching the injector reason circumference on and unpremeditated.

When the injector is acid on, it unreserveds, spraying atomized fuel at the tail face of the ingrasp valve.

As fuel is sprayed into the ingrasp couragestream, it mixes with the infuture courage and vaporizes attributable to the poor constrainings in the ingrasp varied. The ECU signals the injector to pronounce honorable ample fuel to close an chimerical courage/fuel pertinency of 14.7:1, repeatedly referruddy to as stoichiometry.

The nice total of fuel pronounceed to the engine is a influence of ECU administer.

The ECU designates the basic introduction division based upon estimated ingrasp courage dimensions and engine rpm.

Depending on engine generous provisions, introduction division succeed differ. The ECU monitors variables such as coolant region, engine expedite, extinguish determination, and empty oxygen earning and makes introduction improveions which designate latest introduction division.


Here’s what is demandd ce spendive conversion

EFI acme and ingrasp varied with everysubject stationary detaild.

Crossover tube, MAF sensor and courage box

Fuel tank with fuel cross-examine

Entire wiring impede from the car.

EFI computer

EFI distributor

EFI coil/igniter

EFI probe fixed in the grant

Knock sensor, ocean relief

Anysubject else that was detaild to the wiring impede

Other subjects which are as-well essential

LC Engineering EFI Pro cam

Fel Pro acme gasket fixed


These are the steps

Quenched with the old…

Courage cleaner unpremeditated

valve shield unpremeditated

Acme unpremeditated

Acme on the coast with the ingrasp removed.

EFI ingrasp and EFI acme

Carb acme and EFI components invested

Certain paltry subjects that we establish were divergent were:

There was some rank of smog project bolted to where the EFI fuel distil goes. It isnt representationd with EFI and was discarded as were the courage tubes that go overhead the acmeer.

The haughty constraining fuel course has to be either made or salvaged.

The vacuum hose ce the brake booster is divergent betwixt carb and EFI.

The conspicuous radiator hose is divergent betwixt carb and EFI

The good-tempered-natured-naturuddy subject is that bcourse of the ceases that go into the computer can be irreferring-to and are merely go to the engine. So, if you uncease these from the intake, then draw the ingrasp sacred. The third cease has the influence and other subjects going to it ce the EFI.

All frolic is to grasp your date and impede each wire future quenched of the computer.

There seems to be merely 3 components quenchedface of the “normal” EFI nonsense. 

The ocean EFI relief located in the toward melt panel beneath the driver’s face grant. The circumference space relief located beneath the voyager face grant. This is administerled by the MAF sensor and turns on and unpremeditated the fuel cross-examine. It is as-well tied into the ocean EFI relief.

The solenoid resistor is alike to a switched influence beginning (IGN) and goes to the fuel injectors. This is located in the engine division passneger face.

Pretty considerable, the merely subject that is referable attributable attributable attributable right ceward is how these three components are wired. 

Mathematical Cemulation;

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Most EFI plans enjoy a gauge fixed of sensors. These include:

The Barometric Constraining (BARO) Sensor, which provides the ECU with the eternal courage constraining lection.

The Engine Coolant Region (ECT) Sensor, which provides the ECU with the engine’s vulgar generous region. This is relevant owing fuel vaporization varies ce divergent engine regions. A calm engine demands over fuel suitableness a fiery engine demands hither.

The Ingrasp Courage Region (IAT) Sensor, which the ECU needs to grasp into recital when determining pulse space.

The Mass Courage Issue (MAF) Sensor, which is a tube collocationed succeeding the courage distil in the courage ingrasp duct. The MAF sensor has a superior platinum wire that spans athwart the tube. The wire is keen by electrical vulgar to oceantain a steady region overhead ambient. The courage issue spent the wire cools the wire and over vulgar is demandd to oceantain the steady region. Thus, the total of vulgar demandd to oceantain the steady region indicates the courage issue reprimand. The courage issue reprimand is separated by RPM to designate the pulse space.

The Varied Absolute Constraining (MAP) Sensor, which representations varied vacuum to estimate engine commit. An EFI plan that representations a MAP sensor does referable attributable attributable attributable demand a MAF sensor as it can representation the input from the MAP sensor to designate the demandd pulse space.

The Oxygen Sensor (O2S), which is representationd to estimate the total of oxygen that is referable attributable attributable attributable consumed during arson. This is relevant ce the improve agency of the catalyst converter and is representationd ce emissions administer rather than deed or distribution. The O2S is located in the empty plan and is an succeeding-the-fact estimate of the courage/fuel pertinency. As-well considerable unburnt fuel in the empty indicates a barren compromise suitableness as-well trivial oxygen indicates a generous compromise.

The Crankshaft Collocation (CKP) Sensor, which is relevant ce timing purposes as it tells the ECU which atom cease to being and which injector to unreserved at any fond apex in the Otto cycle.

The Extinguish Collocation (TP) Sensor, which is another relevant sensor as the extinguish collocation and the reprimand of transmute in the extinguish collocation indicates the what the diver nonproductions the car to do.

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The modifications we can enact on an OEM EFI are slightly scant owing the OEM ECU is referable attributable reprogrammable. However, there are a enumerate of subjects we versed that we unimpassioned engineers do to disagree the EFI plan withquenched having to reprogram the ECU. We can extension the fuel constraining as this is individual lection that the ECU of a regular efi kit representationd in the cultus eg does referable attributable attributable attributable grasp into recital – it assumes the fuel constraining is a steady 30 psi(an estimated estimate fond by Pak Suzuki ) overhead ingrasp varied constraining; we can intercept the pulse signal form the ECU, deviate it using input from the varied constraining and grant it to the injector; we can extension the injector nozzle size; or  extension the enumerate of injectors. However, your best discretion, deed prudent, is to invest an aftermarket ECU. In the present scant pages we’ll sift-canvass each of these discretions.

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There are a scant relevant factors that our consider shows that must be graspn into recital when installing an efi engine. These are: the pulse space of the injectors and the function cycle.

The injector pulse space is the total of date that the injector is held unreserved so that it can inject fuel into the arson lodging. The pulse space is administerled by the engine administer individual (ECU) and is hanging on diverse sensors in the electronic fuel introduction (EFI) plan. The longer the pulse space, the over fuel is adventitious to the courage/fuel compromise. The total of fuel demandd at any individual date varies by the total of courage issue, the courage blindness, the engine commit, and the engine region. Therefore the pulse space succeed differ. However, there is merely a scant total of date that the injector can be held unreserved at each manner of the engine. This total of date is degraded as engine expedite increases. Ce specimen, at 600 RPM the advantageous date is 0.1 seconds (60 seconds in a diminutive separated by 600 manners) save at 6,000 RPM it is merely 0.01 seconds. The pulse space referring-to to the advantageous date at the engine ruddy course is denominated the function cycle and is developed as a percentage. Thus a function cycle of 80% media that at the engine ruddy course the pulse space (the total of date the injector is succor unreserved) is 80% of the advantageous date.

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Deed ECU Bits

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Replacing the store ECU bit with a reprogrammed deed bit is a good-tempered-natured-naturuddy discretion ce anysubject up to a 10% extension in engine influence. This is oceanly attributable to the cem in which the store ECU bit is programmed. In substance, the store ECU is programmed ce optimal deed at peak torque so as this ensures that the car is drivable at poor engine expedites. As most cars would be driven at poor engine expedites of up to 3,500 RPM, ensuring that the car drives completely at these engine expedites is completely reasonable; unhither you nonproduction to disagree your car! A reprogrammed deed bit succeed be programmed ce optimal deed up to the engine ruddy course, releasing a modereprimand influence extension save making the car hither drivable at poorer engine expedites.

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The fuel pickup should as-well gain some importance, specially on a qualified street course car with a steel fuel tank. On such vehicles the fuel smooth in the fuel tank can descend bepoor the fuel pickup during unfeeling cornering or depressed succor and depressed braking and can carepresentation a fleeting descend in fuel constraining and engine deed. The disintegration is to enjoy a induced fuel cross-examine contribute a paltry fuel reservoir or swirl pot that feels the pristine fuel cross-examines. The fuel reservoir is a absolute cylinder with an fuel ingress from the induced cross-examine at the face, a fuel requite course at the apex and fuel pickup courses to the pristine cross-examines at the deep. The fuel reservoir should enjoy a calibre of at meanest 1 liter and should be mounted poor, beface the fuel tank. With a fuel reservoir, the pristine fuel cross-examines succeed constantly enjoy a fuel contribute equal beneath unfeeling cornering of depressed succor and braking provisions.

Calculation on this bases were dindividual and were utilized in MATLAB program

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