Fuel injection for my ATV
paysonbadboy
Posts: 81
· Hey all. After WANTING to learn to use these things for years,·I FINALLY bought one.
I got the BOE with the sx chip. Seems to be more than enough for most of what i will be doing.
So after staying up late last night going through EVERY PBASIC section of the Basic Stamp manual I am starting to remember some of the basic language i played with 20 years ago on my tandy color computer (one that plugged into the TV!)
So. Some of it's making sense to me and I've got some to learn. Electronics has always been a hobby of mine.
Anyway. A few months back·I started to think up a way to make Fuel injection for my yamaha 4 stroke. I HATE rejetting the thing when I go from Home (Phoenix) to Norhtern AZ (7000 ft altitude!), etc.
So·I wound up with a circuit board with like 5 IC chips and numberous other parts. My brain started to hurt from trying to THINK the thing thorugh. trying to make something to use feedback to vary pulse width was getting hard. So·I left it alone for a while then finally bought this thing this week.
After reading the PBASIC manual the last two days I actually think this project may be sort of EASY to think up. and now any adjustments will be PROGRAMMING instead of pulling compnents and soldering in something else.
Anyway. Give me a few months or so to learn this thing better and maybe I'll be posting my results.
I'll also cruise around in here to see what others are making.
I love these things. I'm excited to finally be experimenting with these things :-)·
·
I got the BOE with the sx chip. Seems to be more than enough for most of what i will be doing.
So after staying up late last night going through EVERY PBASIC section of the Basic Stamp manual I am starting to remember some of the basic language i played with 20 years ago on my tandy color computer (one that plugged into the TV!)
So. Some of it's making sense to me and I've got some to learn. Electronics has always been a hobby of mine.
Anyway. A few months back·I started to think up a way to make Fuel injection for my yamaha 4 stroke. I HATE rejetting the thing when I go from Home (Phoenix) to Norhtern AZ (7000 ft altitude!), etc.
So·I wound up with a circuit board with like 5 IC chips and numberous other parts. My brain started to hurt from trying to THINK the thing thorugh. trying to make something to use feedback to vary pulse width was getting hard. So·I left it alone for a while then finally bought this thing this week.
After reading the PBASIC manual the last two days I actually think this project may be sort of EASY to think up. and now any adjustments will be PROGRAMMING instead of pulling compnents and soldering in something else.
Anyway. Give me a few months or so to learn this thing better and maybe I'll be posting my results.
I'll also cruise around in here to see what others are making.
I love these things. I'm excited to finally be experimenting with these things :-)·
·
Comments
I thought I saw a link or post (might've been back on the yahoo groups) about someone putting fuel injection on a go cart.· Remembering, I think it was just a lawnmower engine (like most are) so just a 2stroke.
Even though there is a PWM command the higher end RPMs for 'quick maneovering' would be too fast for the stamp, me thinks!·
You would have to read inputs (crankshafts/cams?? and throttle) and then output the desired Pulse....but if you are running a 4cyl then at 1000RPM you'd be firing out 4000pulses....so you'd certainly need some external IC's.· The PWMpal might be an option (parallax sells it).
An ATV must have a flywheel...no?· Find TDC and BDC and maybe put some magnets and hall affect sensors to send position to help in the firing sequence.·
If you don't want to butcher in to your ATV just yet, then try your lawnmower (or a crappy one someone is replacing) and start with a 2-stroke to start.
I've agot a book at work on automotive electronics, I'll take a peak and see what tips it might have on injection control.
welcome to stamps!
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Steve
http://members.rogers.com/steve.brady
"Inside each and every one of us is our one, true authentic swing. Something we was born with. Something that's ours and ours alone. Something that can't be learned... something that's got to be remembered."
One spark per every TWO revolutions and remember 6000 RPM's is 6000 per MINUTE or 100 revolutions per second.
A four cylinder four stroke would be firing 200 pulses per second at 6000 RPM's which·I think would be possible.
There's my test setup I did today. So far I ALREADY had a hall effect cam sensor I installed months ago. It doesn't ineterfere with running the stock carb. So I used a very basic test program using a constant pulse width to fire the injector via a IRFZ44 mosfet.
I worked fine. But Ididn't have it installed. the fuel injector i had just spraying fuel into the air! I'd go change the pulse width settings (pulseout) and watch it spray more or less. The only parts i used was the BOE board, a mosfet, and a seperate board with a OP AMP used to interface the small signal from the hall effect sensor to a 5 volt pulse to feed the controller.
This week I'll try to take the quad apart and make some adapter to mount the fuel injector.
and in the end i hope to use math to change the pulse width (variable) and posibly a o2 sensor and maybe a throttle sensor. All parts I already have but haven't made fit yet. Yet!
I'm assuming even the standard PBASIC2 controller will be sufficient. What i had there was a sx.
I save ALL of my projects as·I go on my website.
Here's my test from earlier... short video
http://www.paysonarizona.net/Home Videos/Warrior_1st_EFI_Test_012305.wmv
Post Edited (paysonbadboy) : 1/24/2005 5:57:32 AM GMT
Any thoughts on protection from the EMI from the spark?·
I don't know if the spark will fire noise up the injectors and down their lines (if metal armored?!)....but this might get back to your stamp and possibly do damage.
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Steve
http://members.rogers.com/steve.brady
"Inside each and every one of us is our one, true authentic swing. Something we was born with. Something that's ours and ours alone. Something that can't be learned... something that's got to be remembered."
The injector will plug into the intake runner just behind the intake valve under the gas tank.
If there's a lot of noise, I guess I could find some zener diodes to hook up to supress out the higher voltages.
Once I get the sensors installed and communicating with the BOE which has my sx stamp I'll design and etch the board which will have a socket for the stamp and a DB9 built in too for programming.
I've got a pair of PBASIC2 stamps coming that I got on ebay for $50 for both. I'm wanting to use those. But from what I understand the timing is different based on those compared to the sx. so that means i can't get it fine tuned with the sx and then throw in the other stamp. So if I get the parts installed and start programming before i get the other stamps I'll only program the basics just to get it running.
I'll post some more pics as I go.
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http://www.paysonarizona.net/
Do you have a fuel regulator? Cars use a vacuum controlled fuel regulator to increase or decrease fuel pressure in the fuel rail. Increase pressure when under load (acceleration) decrease when load is removed
Question/thought - If pulse width at injector stays constant and I vary fuel pressure won’t the volume of fuel injected change?
Then if the above is true would the opposite be true? – If I increase pulse width at the injector with out increasing pressure there will not be enough fuel to meet demand (lean) Also if I decrease pulse width and don’t lower fuel pressure I will have more than needed (rich)
Have you considered a return line to tank to reduce load on pump?
Also I thank you will need a MAP sensor (Manifold, Atmosphere Pressure). Compares manifold vacuum to atmospheric pressure. Helps to confirm load and throttle position. Load vacuum increase. Throttle slammed open vacuum drops in both cases need more fuel. This would be needed to regulate fuel needs based on altitude.
Just some of my thoughts as I have thought about fuel injection for small engines. It seems to me that the extra cost for fuel, sensors, and control have kept its use from small engines on lawnmowers, ATVs weed eaters and the like.
Having ridden ATVs and Motorcycles I know the frustration of rejecting a carb. I’m looking forward to following your progress.
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Tony
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I have a small pump as with all the sensors EXCEPT for a MAP sensor.
Tonight I just temporarily hooked up the injector into the intake runner between the carb and head. Drained all the fuel from the carb.
Here's the injector i used. Later i need to sleeve a piece of copper into that intake runner so the injector will have a good seal and something to mount to.
here's the inlet side of my stock carb. It's a large carb and the slider is rectangular instead of round like what I've seen before.
This is the outlet of the carb. Low and behold it has a throttle blade. So I'll be removing the slider and needle to use this as a Throttle Body only.
Cars of course have more in mind than just correct engine operation. they control emmisions which is nothing I need to worry about.
Early Electronic Fuel injection was pretty simple some being mechanical. But·I once helped a friend pull a multi port EFI engine from a 1972 or so Volvo and put it on his 1966 Volvo. It actually had a few POTS to turn on it's PCM.
Anyway. At first I'm not going to bother changing fuel pressure. I'll leave it at a fixed pressure which happens to be 100% right now. My pump may have built in regulator anyway. I should be able to vary the pulse width quite a bit and get enough fuel even without increasing pressure.
I varied the pulse width and it DEFINITLY made a difference.·I KNOW I can turn it down enough to really lean it out and full pressure should surely be enough for a wider pulse width to be sufficient. I DO have the vacuum controlled regulator attached to a fuel rail from the multiple junk yard parts·I bought months back.
Here are two short videos i made tonight after work when i hooked the stuff up to test.
these are the first starts on the EFI. No feedback tho. just using the cam sensor only and the fixed pulse width·I mentioned. later·I will impliment the feedback of TPS, O2 sensor and make adjustments with them and RPM's, etc. Once·I get the sensors working I'll just need program tweeks.
http://www.paysonarizona.net/Home%20Videos/012405_1st_start_01_TooRichToIdleProperly.wmv
1st run it ran ok but idled too rich.
So·I reprogrammed a wider pulse width. Remember it's fixed right now. Very simple program of like 10 lines if that.
http://www.paysonarizona.net/Home%20Videos/012405_2nd_Start_IdlesProperly.wmv
On the 2nd run it idled great but would cut out when·I opened the throttle but I expected that with it not enriching the fuel.
It's still pretty exciting. I've had a Micro Controller for less than a week and I think I've learned a lot so far.
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http://www.paysonarizona.net/
Post Edited (paysonbadboy) : 1/25/2005 5:13:27 AM GMT