How does Fuel Injection Work?

[Kiwi_Roy]

Dare we try to explain this or should I not try?

Are there any good explanations out there?
 

[kingoffleece]

https://auto.howstuffworks.com/fuel-injection.htm

Start here.

[Kiwi_Roy]

https://auto.howstuffworks.com/fuel-injection.htm

Start here.

Sorry KOF, doesn't even come close

Roy

[FarmallA]

Bosch Fuel Injection & Engine Management: Theory of Operation, Troubleshooting and Service Using Common Tools and Equipment, High Performance Tuning, Author Charles Probst. 

Available wherever you buy books.

FarmallA
Steve

[kingoffleece]

No need to be sorry.  It was a start-to an extremely complicated subject.
The dive is very deep.

[John A]

Bosch Fuel Injection & Engine Management: Theory of Operation, Troubleshooting and Service Using Common Tools and Equipment, High Performance Tuning, Author Charles Probst. 

Available wherever you buy books.

FarmallA
Steve

Thanks, I’ll check that out. I have a Bosch automotive handbook that is my go to for information. It describes fuel injection, lights, terminal designation ,suspension, everything in great detail. I’ll post the title tomorrow

[Kiwi_Roy]

As an instrumentation consultant i'm familiar with selecting control valves I understand how flow through the injectors is restricted by Choked flow
It also explains why the pressure at the injectors is set to around 40 psi (choked flow region), if you were to double the pressure the flow only goes up a tiny bit.
Because of that the ECU knows how much fuel is being used. flow rate x Injector open time.
Fuel flow and speed over the ground lets the ECU calculate MPG or metric equivalent Litres / 100KM KM/L (my V7III displays Km / L)

About 10 Years ago I assembled a MyECU kitset put out by Cliff Jefferies in Australia I used it on my Green VII Sport, Cliff is a Guzzi owner who accidentally fried the ECU, he wasn't happy about the replacement so decided to build his own, they are shipped all over the world.
His site had quite a good description of how the ECU works.
here's a link
https://www.myecu.biz/MyECU/index.htm
I suggest you read
About MyECU and How it Works

[n3303j]

What's to explain?
It's a computer controlled atomizer that sprays gas when and where you need it.

Certainly a lot simpler than a carburetor.

[guzzisteve]

It just does. With the right map, size injectors, and good sensors.

I have a MyECU and it reads Microsoft Word.

[Antietam Classic Cycle]

Black Magic. 

[wirespokes]

Black Magic. 

I'm with you there!

Carbs may be more complex than an injector, but all that delicate computer nonsense, sensors, high pressure fuel, etc makes it all much more complex. Compared to all that, a carburetor is pretty simple!

[AJ Huff]

Years ago there was someone here looking to build their own EFI system for a Guzzi. I think based on the Megasquirt. I'm not sure he ever finished or was successful.

-AJ

[n3303j]

I'm with you there!

Carbs may be more complex than an injector, but all that delicate computer nonsense, sensors, high pressure fuel, etc makes it all much more complex. Compared to all that, a carburetor is pretty simple!

FI is simply a solenoid controlled atomizer fed by a constant volume positive displacement pump with a bypass pressure regulator. The computer receives air pressure, temperature, exhaust gas information,  requested theottle settings and rpm readings from reliable solid state sensors. The only complexity in the whole system is the firmware that supplies solutions based on received data. That is hard coded by the manufacturer and as such is a stable condition. Couldn't be simpler.

Carbs have to come up with all the solutions based only on their mechanical configuration. They are a compromise at best. Change one parameter and the remaining ones shift. The new solution requires mechanical changes.

On EFI if you change a parameter it's a simple matter of adjusting the program. No jets, needles, or any other wrench type stuff. Maybe multiple programs for cruise, sport, economy, etc. Can't do that with a carb.

[normzone]

Or in other words, the original Suck Squish Bang Blow sequences have an additional Squirt added.

[n3303j]

Or in other words, the original Suck Squish Bang Blow sequences have an additional Squirt added.

Most of the times suck & squirt occurs in the same window. Some engines are putting squirt in at top of squish (diesels & Kia).

[nc43bsa]

Black Magic. 

It's only black magic when it's extremely rich.

[Kiwi_Roy]

It just does. With the right map, size injectors, and good sensors.

I have a MyECU and it reads Microsoft Word.

That's clever, Cliff has added a number of innovated ideas to the MyECU over the years.

[Kiwi_Roy]

I think this thread is starting to go sideways, bugger!

[elrealistico]

FM

[RinkRat II]

  Hi Roy, are you looking for general principals of operation or more detailed info on programming maps controls etc.?

     Paul B

[John A]

Here is some pics from that Bosch handbook. It describes electronic and mechanical fuel injection in detail