PLEASE, 'Splain Me

[Fla._Deadheader]

 I'm studying and playing with an idea.

  Could anyone or all of Y'all, "splain me how this Electronic Fuel injection works. How it atomizes the fuel, and how it's timed. Can the timing be drastically changed

  Be as technical as possible 

[olyman]

you can change the timing on a car fuel injected by "reburning" the computer----any fuel injected engine can be changed--if you can hook into the computer!!!

[stonebroke]

As I understand it, Electronic fuel injection is a solenoid that opens and closes the injector. it is controlled by sensors on the crankshaft that tell the computer where the pistons and valves are. it is really a better way than the old mech. systems that were linked by gears and could not be adjusted on the go.

Stonebroke

[Fla._Deadheader]

 OK. Where does the pressure come from, and how much

  Is there a seperate injection pump

[stonebroke]

The pressure comes from the injection pump. The pressures on modern diesels are very high. The electronic part is just to control the fuel flow.

Stonebroke

[Fla._Deadheader]

 What about so-called fuel injection on gasoline engines   What are the thingys in the throttle body, and if they are injectors, where is THAT pump   Could they be used for direct injection

[low_48]

The fuel pump on a car is in the tank. I think they are all vane pumps. Here's a pretty good link;
http://auto.howstuffworks.com/fuel-injection.htm

[amberwood]

Ok
it can be supplied in two ways
low pressure pump usually in the tank, then a high pressure pump down the line to feed the injectors, or just a high pressure pump in the tank.

electricaly controlled injectors, usually one per cylinder for OEM squirting into the manifold, idealy at the back on the inlet valve, but depends upon the manufacturer and packaging requirements. Higher spec vehicles may have multiple injectors per cylinder to supply more accurate fuel delivery at low demand, then bring on more injectors for high demand high HP use.

An ECU or computer to control the whole mess, relies on inputs from external sources such as throttle position, water and air temp, manifold presure, exhaust temp, o2 sensors, air flow meters, fuel pressure etc etc. It depends alot on the age of the system and the manufacturer. Most OEM ECU's can be reburned to change the program, or piggyback ECU or chips can be changed, or you can replace the whole ECU with one from MOTEC or similiar.

confusing?

DTR

[logwalker]

Our turn, why are you wanting to change the timing? Joe

[Fla._Deadheader]

 I want to inject water vapor at BDC.

[logwalker]

What happens to the H2O at BDC? Have you looked into Bruce Crower's 6 stroke cycle engine? Joe

http://www.autoweek.com/apps/pbcs.dll/article?AID=/20060227/FREE/302270007/1023/THISWEEKSISSUE

[flip]

Normal gas fuel injection uses 40-60 psi for pressure.  If you ever take an injector out the atomization holes are very very small. Fuel pressure is on the injector at all times and the computer determines, in miliseconds, how long to open the injector. Timing is determined by engine RPM, engine temp., throttle position, ambient temp., quantity of air entering the engine, barometric pressure, oxygen sensor feedback.  They shoot in right above the intake valve.  Now if you are feeling saucy look at NOS (nitrous oxide systems) set up.  They bore a hole in the intake in each runner for fuel injected systems to inject the nitrous, carb systems use a place under the carb.  Problem with that is it dumps in all cylinders all at once, no regulation or timing.  If you inject water on the intake stroke, unless you have some sophisticated engine management systems, you will be diluting the atomized fuel and putting out the fire.  Not saying it can't be done but you would need to engineer a timed delivery system, independant of the fuel deliver system which would be piggy backed to a cam sensor or crank sensor.  I don't even want to get into the situation if one of the water injectors sticks open, Mr. Rod will come out for a visit

[Fla._Deadheader]

 I used to run an 8 cycle engine. 

  My idea is way past what I want to explain. I just would like to know the answers to my questions, for now. Later, IF I get this to work, I have a list of folks here that I will share with.

  My world, right now, is running in many different circles. This is why I need y'all's help.

 

Not saying it can't be done but you would need to engineer a timed delivery system, independant of the fuel deliver system which would be piggy backed to a cam sensor or crank sensor

  Flip, this is EXACTLY what I am talking about. 

[flip]

Most sensor systems run off of a 5 volt reference system.  I guess I don't see any reason you couldn't tap into the cam or crank sensor and use that as your timing device.  You would need to be able to advance or retard your water injection based on that signal for proper combustion, which is where some type of mgt. system would be needed.  Not impossible but very intriguing....what kind of debauchery are you up to

[Fla._Deadheader]

 

what kind of debauchery are you up to

  Right now, I'd rather not divulge my idea. 

  Got any devices in mind that I could read up on   Anyone

[flip]

What kind of vehicle or application.  Model years.  Engine sizes?

The world I know with Ford, our diagnostic equipment is about 7G a wack.  But we are not able to modify or tweak any settings, just monitor and reprogram if there is an update for the software.  I know there are things out there that people are using to get in and change some settings but am not sure who they are or what type of software they use.  I can get EEC 5 or OBD 2 cables for a lap top no prob. but need to know what kind of veh. you're playing with.

http://wiki.xtronics.com/index.php/EFI_ECU_FAQ

This may be a starting point...

[Fla._Deadheader]

 Alright, I know you are really trying to help me, so, I am wanting to add water vapor injection to my '78 Land Cruiser Diesel. Injecting at BDC will cause the vapor to increase in volume as the piston rises and compresses, in the cylinder. As this happens, the vapor will flash to steam, and as the cylinder fires, you get a LARGE increase in power from the expanded steam vapor.

  That's why I need a seperate injection system.

[flip]

OK, diesel.  I know the tractor pulling guys use this for extra bang, let me look here...

http://www.scheiddiesel.com/waterinjection.htm

Scheid is not too far from me and one of our parts guys worked for them for a while.  This should be near the same principal.  I would think you could probably fog in the water mist into the intake and let vacuum from the intake stroke do the rest.  All you need is a way to atomize and regulate.  You may not need computer controls knowing the rest of the story.   In a house I use to live there was a humidifier nozzel installed that was about the size of a shirt button, small hole, very fine mist and just used house water pressure. Hmmm, let me do some more thinking.

[Fla._Deadheader]

 I'm sure that misting into the manifold, on a diesel, is not real effective, because of the lack of vacuum. It NEEDS to be injected at the BOTTOM of the stroke. When compressed, it makes a somewhat superheated steam, that gives a LOT of uumph to the power stroke.

[beenthere]

Interesting idea Harold.

Here is another discussion, that seems related to what you are investigating.

http://forums.tdiclub.com/showthread.php?s=11a86be56faba954b45a6e116cf7bb8f&t=202520

To me, compressing steam makes me think of a lot of engine knock...   I like your thoughts tho.