Craftsman 12HP Fuel Injection -Project

[jhark]

Friends and family said this would'nt work...LOL

Well, I got tired of messing with the carb every season on my craftsman. So I walked over to my Oldsmobile Van and poped a fuel injector out of the fuel rail along with the wires.
Drill and tap the intake of the lawn mower and installed the GM Injector. Now the carb works as a thottle body. I then wrote code for an Arduino micro controler to run the injector and monitor sensors(like an ECU on a car). Here is a picture of the workbench prior to the install.



I used a ULN2003 IC Chip to drive the injector, and a pot to change the pulse width. The mower started on the first try and after 3 code adjustments it would idle smoothly using 5ms injector pulses with 20ms between each pulse. I tied a pot to the govner to monitor throttle position. When the governor moves addind air, the Adruino micro controller responds by increasing the pulse width keeping the fuel mixture correct.




To start the mower I set the pulse width to 5ms with the pot on my control panel. Thats the amount needed for idle condition. When I want to mow or engage the mower deck I turn the pulse width up to 11 or 12ms and raise the throtle lever to full throtle this opens my throtle body(old carb) about 10%. From here the governor and the code below handle everything else. If the engine goes under load the governor kicks in and opens the throtle body turning the pot connected to the governor, so if the governor pot reads 980 I subtract that from 1000 and add it to the value of my fuel trim pot, now we have 1000-980+11 = 31ms injector pulse. Then the engine RPM's recover and the govner pulls back to 1000.
I really need to do a youtube video of this cutting the lawn.
Best of all ----> Next year my mower will start up and run
I will be putting togather a schematic soon..

The pump is a Mr. Gasket 7 psi. Before installing the injector I played with the pulse width by watching the spray patern on a piece of paper. My findings were that lots of small squirts are much better then longer ones, 2ms pulses are hardly visable and 100ms pulses are like pulling the trigger on a windex bottle.



Well, This project is working 100%. The control panel is mounted, wires are all cleaned up and encased. Today I mowed the lawn/weeds with my fuel injected mower. It has never ran better or had the power that it has now. The seat out of my old van welded on makes for a smooth ride. I also added (3) switches on the control panel, Arduino Power ON/OFF, Fuel Pump ON/OFF and Injector ON/Off

[Tencubed]

If you could make a kit that would allow a computer dunce like me to put that system on a single or two cylinder engine I'd suspect you'd sell them like hot dogs at a ball game.

One of the better ideas and builds I've seen in awhile.

Mike

[larrybl]

Yes!!!!! Great project I would be on the list for a 18HP twin in a heart beat. Carb needs major work.

[czd3my]

I have done Megasquirt on a few cars and have an MSII with a wideband O2 sitting around. I was sure thinking about running my Onan twin on it. You just made it worse for me! That is really cool! Does that controller have maps on it? I wondered if you could use a switch on the engagement lever for the deck to trigger an enrichment? Just thinking...

[TUDOR]

Excellent!!!

Now if your looking for opportunities to fine tune it on a twin, I have an Onan 20 hp.

I think that you've stumbled on a ready market for this idea, and lots of possibilities for R&D on different engines to prove it out prior to marketing. I don't think that you'll have any shortage of volunteers.

Please keep us informed!!

Bob

[jason4567]

What an awesome idea!!! I think I'm going to have to fool around with this over the summer, I have an old 5HP RER that needs some serious carb work. Maybe this would be a better(and certainly cooler) soulution.

Jason

[madmantrapper]

I'm sure it is already patented.

[ben2go]

Micro Squirt works like a dream on small engines.You can control injection and ignition.A B&S 16hp opposed twin can make 20hp running E85,custom open headers,Accel coils for a Harley,8:1 compression,and a smoothed port heads.This was dyno'd before and after.I saw the dyno print out.I am not sure what throttle body or coil trigger was used.The engine was going on a racing mower.It was the 16hp B&S opposed twin used on most MTD products through the 90's.The govenor was retained to meet class rules.

[jhark]

Thanks for all the great comments,
I will gladly post/share the controller code and schematic. This could be adapted to any motor including twin cylinder. The driver chip has plenty of outputs for another injector. The arduino micro is cheap and easy to work with, this was my first project with it.. I would like to (someday) use the arduino with a gps and sonar(tree avoidance) modules, and program the mower to take care of the lawn without me on it.. this would also require an extra battery to run the steering servos.
sounds a bit crazy.. but thats me
--Joe

[Boyd]

Originally Posted by jhark

Thanks for all the great comments,
I will gladly post/share the controller code and schematic. This could be adapted to any motor including twin cylinder. The driver chip has plenty of outputs for another injector. The arduino micro is cheap and easy to work with, this was my first project with it.. I would like to (someday) use the arduino with a gps and sonar(tree avoidance) modules, and program the mower to take care of the lawn without me on it.. this would also require an extra battery to run the steering servos.
sounds a bit crazy.. but thats me
--Joe

A company in Michigan has been working on an autonomous mower for several years. I haven't checked their website in quite a while. Now if you install direct injection on a mower engine I'll call you Einstein.

[bill3542]

i understand the part about faulty carbs and the fact you like to tinker but you just come up a idea that would only make the repair shops more money because the average joe would have to take it in for repairs or end up having to buy a hand held scan tool at a 100 bucks to read it for problems.
our cars and trucks today are a mechanics nightmare due to this crap from the Federal Govt and EPA, think before you leap.

[Boyd]

Originally Posted by bill3542

i understand the part about faulty carbs and the fact you like to tinker but you just come up a idea that would only make the repair shops more money because the average joe would have to take it in for repairs or end up having to buy a hand held scan tool at a 100 bucks to read it for problems.
our cars and trucks today are a mechanics nightmare due to this crap from the Federal Govt and EPA, think before you leap.

What your talking about "will" happen sometime in the not too distant future. There are large mower engines with EFI, I think they are mostly ZTRs. Catalytic converters will happen and eventually direct injection like what some cars now have. Direct injection is one of the greatest leaps in automotive technology in many years. Smaller engine, higher compression, more horsepower, more efficient, less emissions.

[ThomWV]

I have been riding motorcycles since ... well, let us just say a little more than half a century. I have always done all of my own mechanical work. At the moment my wife and I own two bikes, mine is a full sized Harley and her's is a late model Harley Sportster. Her bike is carbureted and mine is the first fuel injected bike I've ever owned. I will never buy another bike with a carburetor - just plain never. Computer controllers are available for them all over the place and I'm sure the same manufacturer's will jump in the market when injection becomes commonplace on smaller engines. The controllers, which allow you to make minute adjustments to both your fuel and ignition all the way through the RPM band, are very easy to use. As for injection itself, its way simpler for the home mechanic than carburetors and when it comes to performance - and emission control - injection is far superior to carburetion


By the way, I personally thank the EPA and other Government Agencies for cleaning up the air I breath.

[bill3542]

oh yes computerized fuel injection is just so great, tell that to someone i know who shelled out big bucks for a new ECM for a Honda Quad or say in 15 -20 years down the road you need a ECM or fuel injector for your bike or quad and can't find one because its no longer carried or made.
this is already happening to mid-80s to early 90s cars and trucks, i would never buy a bike or quad or mower with this BS installed on it.

ThomWV a peice of advice . never, never trust anything the Feds do, it will cost you in the long run.

[ben2go]

My plan is to microsquirt all four of my motorcycles.Hoping to squeeze all the power out that I can.