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    Hi there, I live in Ca and I suppose you live around my neck of the
    woods, I am up in Sonora, closest airport is Columbia.

    I read your article on the Fuel Injection installation on your rotary
    engine website with big interest.

    I have a VariEze, that I just love, it is very efficient.

    I understand that Klaus S, have a similiar system for sale.

    I want however a sequential Fuel injection system, and he claims that
    his system is not sequential.

    I don't know about rotarys, but in piston engines (I have an O-200),
    the efficiancy will go up if you use a sequential FI system.

    Soooo...looking at your plans on how to build one, I looked and
    looked and finally I decided that the system you are proposing is a
    very good system, and it can be made sequential.

    The key question here is basically, the function of the 555 chip.

    In order for this to work, the 555 chip has to open and close ONES
    per command (Per trigger) .

    I looked at the system, and can conclude that all the indication systems
    can be common, intake pressure probe, etc.

    The only difference actually is that there has to be four triggers,
    instead of one. One for each cylinder, (I know, some more sophisticated
    systems just have one camshaft sensor, but that means I have to ad a
    timer clock, and it will start to be complicated in that way, I want
    to keep it as simple as possible, and have four trigger points is
    not that hard.

    The whole question that will make or fail this project is the way the
    TLC 555 chip works.

    Can you please tell me how it behave once it is triggered, will it start
    pulsing, for a while, (on and off) according to the internal clock, and
    stop after a while...or will the TLC 555 shoot ONCE, after each time
    it is triggered?

    Reason I am asking is that a batch fired system , doesnt really
    matter that much, the injector can sit and pulse, , and shoot fuel
    per the pulses it recieves, no matter if the intake valve is open or
    not.

    That, ( in a piston engine....and I assume also in a Rotary engine) will
    lower the efficiency of the engine, as fuel will be delivered
    differently for each stroke.

    Some intake strokes, will get a little bit, and when the valve
    closes, the injector squirts a bit more, and when the valve opens
    next time, it squirts again, and now the engine is sucking in the
    previous fuel, plus the fuel it is currently delivering.

    So, some strokes will run lean, some is just right, and some is rich.

    Therefore, if I want to build a FI system I want to build the most
    efficient I can do ( Direct fuel injection will be a bit too much
    problem to handle though, so on that I will pass) , and the best I
    can build would be a sequential FI system.

    We will run into another problem here, I will need bigger injectors,
    as a batch fired system have no time restriction on its fuel
    delivery, , but a sequential system has to deliver all the needed
    fuel in a quarter of the time. ( Intake stroke, or the time when the
    intake valve is open.....it actually has a little bit shorter time
    to accomplish this in, as you can not start spraying in fuel, just
    as the intake valve opens, you have still pressure in the cylinder,
     and the full effect of the overlap has not starting to take effect
    just yet.)

    So I have about one fifth of the time to deliver allo the fuel I need.

    Now, as I understand, the size of the injectors doesnt really matter,
    this system can handle it all pretty good, and actually run the
    injectors straight.

    You seem to have already been doing this a little bit, and maybe can
    come up with some general advice on this, but my main question is if
    the TLC 555 chip will trigger once and give one pulse, or if it will
    continue to pulse, after each time it is triggered?

    Also, I live up in the boondocks, and the only thing around here is
    Radio Shack, and they don't have much, are there a good electronic
    retailer around where I can stock up on all the things needed around
    here, ( lets say Stockton, Manteca, Modesto or thereabout)

    I saw from the photos on the website, that you have some goodies, and
    have made a really good set up, circuit boards, good fitting heat
    sinks, and everything, did you do them yourself, or do you have a bunch
    produced, ( for sale) .

    I would appreciate to hear from you, and kick some ideas with you.

    Roger Isaksson

    http://www.rotaryeng.net/simple-cheap-555.html

    I am not sure our approach will work as we have not tested it yet.
    At 7500 RPM one only has about 8 milliseconds to work with for one
    RPM. We are about to test it in the next six months unless something
    more important comes up. I am am not sure how Klaus is doing it.

    DigiKey or Mouser both give fast service on mail orders.
    http://search.digikey.com <http://search.digikey.com/>
    <http://search.digikey.com/
    <http://search.digikey.com/
    <http://search.digikey.com/
    <http://search.digikey.com/
    <http://search.digikey.com/

    We also don't have any parts for sale just yet but you are welcome
    to use our art work to build your own PC boards.

    Frankly I am not sure timed is the way to go. I am about to
    instrument and test another EFI system already sold for use in
    rotary aircraft engines and will know more about that shortly.
    http://www.hytekautomation.ca/

    We will record when the fuel is injected into the manifold relative
    to the e-shaft angle and of course how long the injector is open.
    Manifold pressure will be recorded in several different places
    to check for aerodynamic differences. All of this will be done over
    a range of RPM's using an actual propeller for a load at a rate of
    1000 measurements per second.

    Stay tuned.

    Paul Lamar

    Hi there Roger here again,

    Have been studying up a bit better on the rotary engine, whoops, didn't
    work the way I thought, oh well.... I told you I was a bit weak on it.

    Well I am in this for the FI and the ignition systems, they look great.

    Fourstrokes are my forte, but hey I am eager to learn.

    Ok back to the FI and so on....the FI system I got fired up about,
    do I understand it right that no one have tested it, the one with a 555
    chip???

    Hm...also, I saw another cheapy made and great looking, very simple
    ignition system, and wonder, ...do you think that the diodes can
    light up
    the FI system as well as the magnetic trigger can?

    Been thinking of what bugs most people, when it comes to engines,
     that is ...to be able to start them up.

    So I'm thinking, like in a fourstroke, or perhaps also in the start
    up sequence of a rotary, lets say that under 100 RPM the system
    would go over to a start mode, meaning, in the case of a four
    stroker, ( or perhaps also a Rotary, realize now that I don't know
    half as much about those than I thought, so I better hold my horses
    when it comes to those)...so ok, lets talk fourstroke.

    If in the starting moment, the ignition system would fire every
    minute from 12 o clock to 4 o clock, giving the ignition system
    plenty of chances to arrange a meeting between one oxygen atom (
    comes in pairs) and a fuel molecule, to have a happy marriage.

    Lets say that in the cockpit there would be a three way switch, off ,
    start and run.

    Most probably there would be a second, set of ignition system, most
    probably a set of Slick or Bendix magnetos sitting there, but they would
    in the firing sequence fire with the clicker, and that is pretty
    much on the 12 o clock position, so the magneto could be left alone,
    and on ON.

    The electronic ignition would be set to START.

    Ok there would be a disc, with holes set on two race tracks, and each
    race track would have it's own LED, and sensor, the switch in the
    cockpit would shift between the two LED's and trigger sensor.

    The first start position, would have a disc with a lot of holes in
    it, that would make the trigger fire from 12 o clock to 4 o clock
    several
    times, and now you hand prop the engine, and make the spark plugs
    fire in
    the start mode.

    While the engine is hand propped, the ignition will be served from both
    the magneto independently, and from the electronic ignition that
    would trigger the spark plug very often,from 12 o clock until it
    reaches the 4 o clock position.

    Once the engine starts, the magneto will automatically start firing
    in advance, and the electronic ignition would not do anything else than
    just firing away into an already burning combustion, until the pilot
    have walked back to the cockpit and switched the electronic ignition
    from START to RUN, where the electronic ignition now will fire in unison
    with the magneto.

    One more thing and this will be as good as it will get, able to advance
    the ignition. By a simple mechanical device run by a perhaps small
    stepper motor, the C clip arrangement of the Diode and trigger, can
    be rotated around the periphery of the rotating timing wheel, and
    the setting controlled by the pilot.

    I have some questions.

    - The circuit board I can see in the pictures for the 555 system, did
    you do them yourself, or did you order them somewhere...just wonder how
    I can get my hands on some of them.

    - What pressure sensor are you using for the FI system, it didn't became
    fully clear of the description of those, there was a lot of serial
    numbers on chips, and other electronic components, so maybe I missed
    it, but I am thinking that maybe it wasn't there... could not find it.

    - The adjustable resistor, that will adjust the timing of the FI systems
    firing period and are suppose to sit in the cockpit, is a bit
    unclear to me. Resistance is measured over two points, but the
    resistor described had three legs, and I wonder how the internals of
    that variable resistor is wired?

    Preciate it, and Happy New Year

    Roger Isaksson

    Your starting scheme can be made to work as the photo interrupter
    circuit has a lot flexibility.

    We use about 50 psi so it uses a stock automotive EFI pump and
    regulator.

    I get my circuit boards from http://www.expresspcb.com/
    They have free PC board design software. If you download
    it I can send you the files I have so far and you can buy
    boards from them. Or you can use them as a starting point and
    change them to suite yourself. Here are a couple of jpg of boards
    that I have done. The software is easy to learn.

    The pressure sensor is a $10 Freescale part from Digikey.
    The mpx 4250 data sheet is attached.

    The leaning pot on the dash board is an off the shelf variable
    resister. Try 10K for a wide range of mixtures. It does not change
    the timing but only the pulse width. Narrow for lean wide for rich.
    I modified the ske to show how it works.

    Also an ABS sensor from Pep Boys is cheaper than the Mazda crank
    angle sensor. It works the same.

    If you are using this on a piston engine you will have to sense
    the cam shaft position as it rotates half as fast as the crankshaft.
    a timed one rotor squirts every rotation while a timed one cylinder
    piston
    engine squirts every other rotation so you need to know when
    the piston engine is on the intake stroke. Probably the best
    place to do that is on the mag drive gear. Probably one reason
    Klause does not use a timed injection :) This 555 system does
    not need to be timed. You could let it squirt on either the intake
    stroke or the combustion stroke as the intake valve is closed.
    Another way of doing it is a capacitive spring loaded clamp on an
    ignition wire to sens when the engine is on the combustion stroke.
    You will be on the bleeding edge when you do that as I have
    never used that trick :)

    Paul Lamar

    -- Paul,

    Did study the explanation on the leaning system,, clear as a
    crystal ball, ok got it...thanks.

    Are gathering all the info for ordering all the needed stuff.

    Now the billion Dollar question...

    Here is this pilot sitting in his cockpit and are adjusting the flow
    to the engine...ok good enough,.... but how would he know when he is
    in stochastic range, lean or fat?

    There is simpler systems for cars, where you can just install an
    extra oxygen sensor, and there is a fuel/air mix gauge you can read
    off, but as most aviation based fuel, have quite a bit of lead in it,
     and with leaded fuel, the oxygen sensor will not be long lived, and
    will start showing erroneous values pretty quick.

    If it would not be for that darn lead, the oxygen sensor is probably
    one of the most gallant and excellent solutions, the oxygen sensor,
     is not a switch but a galvanic element, and have very fast reaction
    time, and it reads very precise.

    And it is so darn simple that it is almost ridiculous, an oxygen
    sensor, a needle gauge  up front, and a circuit going through it, that's
    all....hmmm....

    Damn lead.

    Wonder if there is a way around it????

    I am aware of all these "big" solutions that can read air /fuel
    ratios, with throttle position sensor, mass airflow meter, computer
    programmed, and the whole jadijada, but not the simple elegant solution.

    If the pilot can not set his fuel mix to the value he wants, he just
    wouldn't know where he is on the fuel map, he can sit and turn that
    adjustment knob as much as he wishes, but he will never know what he
    will be feeding the engine. All he would know is turning to the left
    would mean leaner, and to the right would mean richer, but he
    wouldn't know, other than getting indications from indirect
    measurements, like cyl head temp, exhaust temp, or listening for
    rough running etc.

    Compared with a carburetor, a FI system is a precision instrument,
    but he would be like a guy sitting with a precision sniper rifle,
     with a high magnification scope, and shooting........
    blindfolded........ all he can do is to aim in the general direction,
     and cause a bang.

    Any thoughts in that direction?

    Roger Isaksson

    Pilots are trained to adjust the mixture according to Exhaust Gas
    Temperature.

    When you start the engine it is rich and the EGT is cool.
    You take off full rich at full power. When you reach cruising
    altitude and want to minimize fuel burn you lean the engine and
    watch the EGT rise. You keep leaning and the EGT reaches a peak
    (stochastic) and starts going down. When it reachs about 50 degree F
    lean of peak the fuel burn or BSFC is the lowest.

    The Holy Grail of EFI systems is to do this automatically. It is
    called auto lean. It was available on turbo compound CW R3350
    air liner recips back in the 1950's. Mistral also offered it
    on the rotary before they went bankrupt.

    Unfortunately Tracy's system does not do this and that is one reason
    it is so hard to tune. Tracy makes a big deal out of tuning the
    engine in the air without a lap top computer in the cockpit but then
    he also uses a crude and cheap manifold pressure sensor as the main
    indicator of the power required. The system cost over $1000 dollars
    so IMHO he could damn well include a mass air flow sensor since they
    are universally included in every car EFI on the planet. The
    manifold pressure sensor sampled by a computer is a one millisecond
    snap shot of what is going one in the turbulent intake manifold at
    that particular time and that specific place in the manifold.

    So far every installation is different as every side port manifold is
    home made. Consequently the mixture map is all over the playing
    field. In the 555 system the pressure sensor does not give us a snapshot
    but automatically averages the manifold pressure readings. A simple
    capacitor can and will improve the average in the 555 system.

    Paul Lamar

    -------------------------------------------------------------------

    thanks read the diagrams of leaning/riching  and the effects of
    temperature , power and economy.

    Yes, you are right ....a mass flow sensor would do a lot of good, but
    ...again, if the exact air/fuel  ratio is known, ...I really don't mind
    setting the mix myself, even if it can be done automatically.

    Dont get me wrong, ...if there is a way to have the mix automatically
    set...I'll take it,....as long as I can, on my own determination bypass
    the auto, and put it in a manual mode, and set it whenever I choose
    to do so....that is, if I could read off a display that would tell
    me in fractions the fuel /air ratio.

    Why a mass flow sensor is not in the 555 system...beats me...when
    thinking of it, ....if a mass flow sensor will determine an exact
    way to distribute fuel, why not substitute the pressure sensor with
    a mass flow sensor.

    I know that the pressure sensor is linear and the mass air flow
    sensor is not, but if one way to measure how much fuel is needed,
     and it happens to be not linear...so what. It is the true ratio, so
    why not.

    What would happen if a mass flow sensor was to substitute the
    pressure sensor in the 555 system?...I mean both the pressure sensor,
     and the mass flow indicator communicates to the rest of the
    electronics in the same way.

    All it is, and both are doing the same thing, either there is a voltage
    or a resistance that goes up or down, ( for the mass airflow sensor,
    a heated wire is used, and that is resistance that changes)

    All we are doing is to look at the same electronic signals, in an effort
    to determine how much fuel we want to squirt in. One measures
    pressure, and takes no consideration of density, , while the other
    measure the true density of the air, and thus will give a true
    representation of the column of air in the intake .

    I mean, what we want is, to give a specific amount of fuel to a specific
    amount of air mass,  what measures that better than a mass air flow
    sensor,... so what if it is not linear, let the FI follow the non linear
    curve. If an instrument can not measure the mass and flow, then it is
    not an mass /flow meter, and I am sure that there are better or worse
    mass air flow meters.

    It might take some research to get a true air flow meter, or find one
    that will actually do the job, because I have a feeling that what
    many call an air flow meter, is only a partial instrument, that will
    work for a specific FI system where there is about a hundred other
    sensors
    involved, but in a stand alone air flow measurement against tuned
    laboratory equipment, they will do either a mediocre or poor job.

    I have a feeling that this is where the "non linear" is emanating
    from, because if it can measure air. and mass, it should not have a
    limitation
    to it, either it can do it or it can't....."well it can measure mass,
    and flow...but not too fast flowing mass" ...  c'mon, don't call
    that a mass flow meter if it cant do what it is suppose to do.

    A true airflow meter, has to accurately measure the actual mass and
    actual flow of the air, if that quantity is known, that's all we really
    need in order to determine the exact fuel delivery.

    It will automatically adjust for barometric pressure, this is the
    automatic system.

    I would say substitute the pressure sensor with a mass airflow sensor
    and this system is licked.

    There are different types of sensors, some have a hot wire only, and
    that's it, some have a hot wire in a little pocket, some have a hot wire
    and a flap that moves and measure the flow, and density at the same
    time, ...VW had one for years that was very reliable, it looked like
    a pressure cockers lid, and when the intake started to suck in, the
    whole
    lid fell down in a recession, on an arm that held the lid from the
    top......either way, I dont know what is the best, as it seems like some
    have a partial function, hot wire only, while some have the whole array
    if measurements, , hot wire ( perhaps pressure also), and flow, with
    a vane, lid or flap. Probably the one that measure the whole
    hulabaloo is the best.

    What if the adjustment knob in the leaning/riching of the FI system had
    a set point on the knob, that could be felt, like a zero point, at that
    point the system would be calibrated to be optimal. When the turning
    knob would reach the middle position a distict "hold" would be felt
    in the knob. That could be a value that is pre determined...lets say
    ( out of the hat) 5000 Ohm or so, anything less will richen,.
    anything more will lean, but always at the "hold" point, there is a
    neutral spot, where the pilot leaves the FI for absolute neutral and
    automatic setting.

    To fine tune that neutral spot where the adjustment knob have a
    "hold" pattern, an inline additional adjustable resistor can be
    attached, ( you know, one of those that you have to set with a very
    small screw driver, that you have to reach into a hole somewhere),
    and when the FI system is at neutral, and the spot is adjusted to
    the "hold" point on the adjustment knob...you're done.

    For fun flying, or going for the hundred Dollar burger, or jumping
    around over the weekend, I would probably not even touch the FI if
    it is self adjusting, but if I would go on a long cruise, I would
    probably
    be very interesting in setting the FI according to my own wishes.

    There is a name that keeps popping up, Tracy, and it has something
    to do with either this 555 FI system or another system of some
    sort....in what way is this man involved with the FI system?

    Is he the guy behind the drawing schematics of the 555 system?
    Roger I.

    Tracy makes an EFI system for aircraft rotaries.
    AKA Real World Solutions.

    I did the schematics on the 555 systems.
    My early version used the mass airflow sensor but I found
    out they were nonlinear. The 555 system requires a linear
    sensor (I think) where power is directly proportional to intake
    manifold pressure. So I switched back to the manifold pressure
    sensor to keep things cheap and simple.

    One can always make a computer controlled EFI system. The Megasquirt
    is a good example of a low cost public domain system.

    I would appreciate some independent experimentation on the 555 system
    as I have my plate full right at the moment.

    I have one RX8 engine test stand that I can try it on. Right at the
    moment I am dealing with some RX8 coil issues trying to get
    it up and running. It has one of Tracy EFI systems so we will do
    a bit of reverse engineering using a data acq system to measure
    such things as coil dwell time and manifold pressure tap locations.

    My friends at Mazdatrix are telling me they are replacing the RX8
    coils with LS2 GM/Denso truck coils with heat sinks left and right :)

    Paul Lamar

    Roger, While you are kicking ideas around I have some suggestions
    learned from a few weeks of Internet searching. I have selected a
    ford mass air flow sensor which is a 2 wire sensor (one heated one
    not) and is compensated for humidity and temperature giving an
    output of 0 to 5 volts. I chose a 5 liter mustang 90MM version with
    a die cast aluminum body and have a late model version with ABS
    housing as an alternative. For input into a computer chip if the
    voltage is converted to digital then cubed plus a fixed number it is
    extremely close to linear over more than the flow range  used by a
    rotary engine.

    Second discovery is the
    Ford EEC series of computer. The earliest were speed density, not the
    best choice. The rest are all mass air flow since 1987. The EEC-IV
    can be reprogrammed by installing a chip on the test port which
    overrides the internal maps. The EEC-V is reprogrammed  by
    reflashing the memory maps.

    The EEC computers are used in racing and that includes some F!
    engines, formula ford and drag racing. No other OEM computers are
    this widely applied. The EEC has two methods of fuel management
    either by mapping tables which are used when not at wide open
    throttle and include the oxygen sensor input as feedback in closed
    loop operation. The tables are in a matrix with each group of inputs
    outputting a value to a higher level map. When the wide open
    throttle contact is closed the system ignores all tables and
    calculates the required fuel only requiring the mass air flow sensor
    and if one is present a manifold absolute sensor and  a barometric
    pressure sensor. For our uses on wide open throttle mode an
    adjustment in the 0-5 volt MAF  output can alter mixture.

       I paid $27 for the MAF sensor and $41 for an EEC-V  from an F250
    truck on E-Bay.  For this same test engine I will be using the EDIS
    ignition also from Ford at a fixed advance as a stand alone system. The
    truck EEC-V was chosen for the eight sequential injector outputs
    which is required on a four rotor Mazda. The four cylinder computers
    are better suited for a two rotor.

    There are at least two rotary engine aircraft using the stock
    RX-7 engine computer. I discounted these solely on the basis of cost.
    They were all more than $300 at salvage yards and I would have required
    two of them for a four rotor. I bought three RX-8 engines and none of
    them came with the computer and the wiring harness was cut off at the
    connectors. The harness is going for $180  which is also discounted
    on the basis of price.

    I drive a truck I bought new in 1987 which is not garage kept and
    have never  had any issues with the engine control systems. I have also
    had two engine failures the same month renting certified aircraft. I
    am therefore more comfortable with a simple, smooth running robust
     rotary
    core engine with automotive systems reliability for control.

    george grimes

    George,

    You are touching on a subject that is all to common in the aircraft
    community.

    Why is your 1987 outside kept truck reliable, when the ...several times
    more expensive aircraft is very maintenance heavy, and have fuel,
    ignition and mechanical related failures more often than then anyone
    like to.

    This is an issue I debated on another forum not too long ago, and I
    think it is mainly from many aircraft owners non understanding of how
    things deteriorate.

    An engine that is run often, like your 1987 truck, will always be coated
    with oil, but I am sure you have gone down the line of aircrafts.
    many parked outside and I am sure you as well as I, and all of us,
    have seen aircrafts that have been parked at the same spot for
    months, and never moved.

    None of them are pickled, at the very best there is a cover over the
    cabin glass, but not over the engine, and they sit there, sit and sit
    and sit.

    Once in a blue moon the owner comes out and start the aircraft and go
    around the pattern.

    Every time he starts that engine it is a demolition derby going on
    inside. There is absolutely no oil , nothing what so ever in the
    engine, everything has gone to the bottom long time ago, and as any
    four stroke can not have any propeller position ( 4 cyl and up)
     where all the valves are closed, you can bet on rust in the bore,
    and valves as well.

    The aircraft has been sitting through a couple of three days rain
    storms, and in between we have the fog.

    The exhaust is very simple and straight compared with cars, and can
    almost be considered a straight exhaust, ( as many in the
    experimental field have) , and internal weather systems WILL develop
    inside that engine, bringing moist to any and all exposed part.

    At least by doing a semi pickled engine, it would protect the engine
    for a long time, simple things, like getting a spray can of engine
    fogger, turn on the starter, ignition off, and spray into the intake
    for a couple of revolutions. That will leave the engine with oil
    that is coated, that will not leave the cylinders or valves, it will
    stick there, and sit and protect the engine.

    There is a lot of engine oil fogger products both in marine and car
    parts stores.

    It is funny, in the marine community this is clear as a crystal ball,
    while the same practice in the flying community, it is clear as mud.

    A simple made plug, into the exhaust pipe will do wonders, and a
    cover that will fit tight over the intake will do the same wonders.

    The majority of airplane engines does never reach the stated overhaul
    hours, before it needs to be overhauled again, while engines sitting
    in trainers, is known to go well beyond 3000 hours, and still run
    strong.

    If you KNOW, you will not run your airplane engine in three, four (
    at most five)  days or more , spray it, and plug the exhaust, and
    intake, if stored in a non heated steel walled building , it gives
    only marginal protection,  use the same routine.

    I don't care if it is a piston engine, rotary engine, steam engine,
     or warp drive engine, that is about the time limit you have, three,
    four,.... five days at most, after that time, you have a dry engine,
    and then you are at risk.

    I used to say, and still make that statement...if it ever rains at your
    location, ever, do it.

    Ok leaving that and back to FI systems,

    George, You seem to have ventured into the Ford systems, and have
    luck with it, and I can see from what you are saying that the Ford
    system
    have probably the most versatile options, suitable for a big range of
    options.

    I will keep that as an option, ( I really will, I will pursue the
    Ford idea based on your description) while looking for a suitable FI
    system.

    I stumbled on the 555 system, and had an idea that it would be a solder
    together type thing, but realize now that this is highly experimental.

    I don't mind to experiment, but I rather have something that I can
    venture straight into, and I am feeling more and more that the 555
    system still needs development.

    I therefore pose a question to the whole rotary community ( or
    others) that have seen the 555 system.

    Are there any workable 555 systems out there, based on the
    description from the rotary website, that is working, and functioning?

    Similar systems work, we know that, Klaus Saviers system works
    wonders, and it could be bought, so could a couple of other systems,
    in kit form, but they are developed to a point where they will work.

    I really like the idea with low Amp draw , no computer, and
    simplicity of the 555 system, and very low cost,  thats a real
    winner in my opinion. The system have all the attributes of a winner,
     but I start to hesitate if I need to be a developer also, ...I can
    do it to some extent, and probably have to, because whatever I get,
    it has to be tuned to my specific application, but are afraid of
    being drawn to heavy into the basic development loop, ....I just
    want an FI system, thats all.

    So, are there any 555 systems up and running now?

    Roger Isaksson

    http://www.team-bhp.com/forum/motorbikes/4615-fuel-injection-india-bikes.html

    However I am a bit more optimistic because a
    fuel injection system is rather simple. A 555 CMOS version is a
    miniature
    fuel injection system in a one dollar 8 pin IC chip. One pin is RPM
    input another zero to five volts input for engine load and a
    variable pulse width comes out another pin for the fuel injector. I
    have enough experience designing computers with IC circuits dating
    back to 1975 so I know it will work. Prior to that I was building
    radio control model airplanes (with tubes) as a teenager in the
    early 1950's. Read the "Who is Paul Lamar" section on my web site to
    see what I have done over the years. http://www.rotaryeng.net/who.html

    BTW I learned to fly Cubs and Champs at age 14 in exchange for
    washing airplanes.

    If you build a 555 system I have time to help by email.

    Paul Lamar

    Roger,

    If you want something you can get up and running fairly quickly, George
    is on
    the right track. The Ford systems are reliable and readily available
    (read
    inexpensive). Ford has a book available on tuning. It is sort of
    directed at
    the Mustang crowd but covers all the systems. It has been a few
    years since
    publication, but what you need is in there. A system for a 4-banger
    is the
    deal. If your AC has dual systems then you install two and can A/B
    them so
    each can be tested at runup individually.

    If you need more fuel flow while running individually, upsize the
    injectors
    for the displacement increase from what the ECU was set up for. That
    will get
    you close.

    You could use the O2 sensor with Mogas during the tuning process.
    There is a
    couple of places to put the potenciometer for leaning. Then remove the
    O2. It
    can be tuned without the O2 also so you can use avgas.

    These are set up since going to sequensial for a MAS. Newer ones are
    designed
    for coil on plug. Nothing wrong with the ones that use the waste
    spark for
    your 0-200. A bit less expensive than the individual coils.

    Dale Davies

    -------------------------------------------------------------

    Dale ,

    I am starting to lean towards doing the 555 system, it's a personal
    challenge...I can see from the correspondence that you all have, that in
    many respects, you are well over my head, and I want to struggle through
    something like this, I really don't mind it, but don't want a big
    research project either, so I think a 555 system will put me about where
    I need to be. ....but by all means, I wouldn't mind looking at the Ford
    system as well, George mentioned it earlier, and I promised to follow up
    on it, where can I get info about the Ford FI system?

    Roger Isaksson

    In my computer experience basing anything on a sole source device
    is sooner or later going to bite you. Manufacturers move on.
    They MUST continue to lower the cost by redesign or go out of
    biz. The 555 is made by half a dozen companies world wide.
    It so ubiquitous you probably have two or three in the house
    with out knowing it :) Look inside the toaster as a start :)

    Paul Lamar



Roger,  To research fuel injection the internet is a good start.
Search  "EEC   EFI   pinout"   or EEC modify tuning" " EEC-IV"
"Ford EFI"  "Ford MAF  EFI" and occasionally add wiki to the search
perameters.  I also bought a book on E-bay called
how to understand, service, and modify Ford fuel injection & electronic
engine control   written by Charles O. Probst, SAE

The one I have is for 1988 to 1993  This book was an easy read and
fairly detailed.  This one is foe EEC-IV only so you might want a newer
edition to cover the EEC-V.  After that the ignition module is
incorporated into the ECM rather than stand alone and a lot of the body
control module functions are interconnected with the engine computer.
They all have on-board-diagnostics. The -IV  and V run with many of the
sensors disconnected such as MAP  EGR  coolant temp, oil pressure and O2
sensors.  The oil temp, and pressure and coolant temp will be on the
glass pannel so sensors will be present  and can also be input to the
EEC-V. The majority of the sensors output 0 to five volts analog and are
converted to digital when input to the EEC module. The module runs on
assembly language which is many times faster than C++ or fortran which
makes sequential injection  calculation in real time. Most of the
sensors we don't necessairly use are only in use at part throttle or
engine start. The MAF and crank angle sensor and if you want the part
load tables used a throttle position sensor.

         I know there is a lot of other stuff in the EEC such as EPROM
chips and RAM and precision voltage control, and then there is the
program itself in the ROM.  All  this stuff is integrated circuit chips,
resisters, diodes, and capacitors and has the possibility of failure
from static electricity. They  are hardened in the case to a small
degree.  All the ignition/EFI systems we are discssing are also made out
of integrated circuit chips, resistors, and capacitors and have the
identicle overvoltage and static electricity vulnerability. I assume the
OEM stuff has Zenir diodes or other components on the inputs to give
some degree of protection and most of the outputs are actually grounding
the various solenoids to complete a circuit so that grounded wireing
doesn't function but is less  likely to damage anything.
        I heard some hanger flying one stormy day that I put down to
wait for weather to pass. Soneone said he would never fly with an
automotive engine with points and a condensor to worry over. He was
oblivoius to te fact his magnetos have these parts still and cars havent
used that technology in 30 years.

       I was going over the material in the link to Tracy's EC-3 and was
impressed with the redundancy and ability to reposition toggle switches
to use the cold start to replace a non functioning injector by firing
the working ones with twice the pulse width.  It also seems that setting
the injector flow rate correction before working on the mapping
adjustments would be the starting point. Getting the mixture knob at the
straight up or neutral point would  seem to reduce the need to offset
the entire fuel mapping adjustment.


george grimes

I think I have that book up in the hangar George. As I recall there
is no source code to the EFI program in that book. Usually that
is a trade secret. Consequently there is no way to change it
and reassemble or recompile it. I had a 1994 V8 Cougar at the time
and I was having trouble with the EFI. Turned out to be a speck
of dust on the hot wire mass airflow sensor. The engine ran fine
except the check engine light would come on.

If I were taking the computer approach I would use ZBasic products.
http://www.zbasic.net/

They have a free BASIC compiler that is very VERY fast. Not fast enough
for timed injection but plenty fast enough for batch injection.
It is real easy to program through a USB port.

As computer languages go it is easy to learn and I can help
anyone with any problem that they may have using it. I have the top
of the line computer and it only cost $90 bucks. Great deal if
somebody wants a VERY powerful control computer.

Can be programed in easy to learn compiled BASIC in weeks rather
than months or years using asm or C. I am pretty proficient already.

Paul Lamar