Megasquirt and MSnS on our EJ powered subies!

[JonOfScio]

So, those who have kept up with Oddcomp and his EA82T wagon running Megasquirt (reffered to now as MS) and EDIS, this is my thread I'm pulling up on how I'm going to get it running on my legacy.

 

At first, the idea of getting fuel control was easy. MS. I have all the things it needs, a tps, cts, need an AIT, my injectors...ect. but to get spark?

 

Well, you could go the edis route. But that's alot more work than what I wanted to do. I wanted to be able to either just use existing sensors (cam or crank angle sensors) to get MSnS (Megasquirt 'n Spark.... spark addon like EDIS is an addon to MS) to run.

 

Well, the crank angle sensor won't work, too many signals per revolution. The cam sensor won't work, because at every 90 degrees is more than one signal output. If the cam had one signal per 90 degrees, it would work, but it doesn't. Look up the diagram in your haynes or chiltons.

 

Ok, solution. Hall effect sensor, peep hole in the timing belt cover, and longer studs with allen key heads for the timing belt sprocket on the cam. It turns one revolution with the cam, would send out the right events, and with longer studs, would allow to send signals properly. So there we have it... the one modification stopping us from putting both fuel and spark from MS on our EJ engine.

 

I soon hope to have enough saved up to purchase everything I will need to get it going. It'll be around $350 for everything. for all the MS stuff, the MSnS add on parts, the wiring, and the palm I want for in car management, associated cables, ect.

 

My first test engine will be an EJ18 outside of a car.

 

Thoughts, opinions?

 

btw - MS now supports up to two wideband O2 sensors... you can have one in each bank of a true dual exhaust... sounds good to me.

[oddcomp]

hehe

[99obw]

What kind of pulse train do you need exactly for the MS? Do the pulses have to correspond to TDC of each cylinder?

 

Can you remove the metal tabs on the crank and/or cam sprockets to eliminate the signal(s) you don't need? You might be able to combine them via some custom electronics to get your desired pulse train. I would be happy to contribute ideas and maybe the hardware if an electronic solution is practical.

 

Is MS open source? Can you change the source code to handle the sube signals and recompile and burn? What processor does the MS use?

 

I have always wanted to build a fuel injection system. Please keep us apprised of your progress.

[oddcomp]

yes ms is open source

think linux but for cars

i need to talk more to the guy that i sent jon to about this ej series dis stuff..

i think tey are both forgetting one tiny thing

with the original dis system i have the trigger ring i have has 36 teeth and a gap

its that gap that the edis module see's and then from that point on the edis unit can tell when teh next ignition event should occur

 

so basically you need the tdc ticks sent to the ms box for ignition and fuel

plus one extra point to mark tdc of number one..

i am prolly well for certain the wrong person to actually explain how it sposed to work

i would suggest www.msefi.com to learn more and do searches on edis patents.. the patent applications tell how the edis actually works

[99obw]

Well, I have looked at a little bit of the MS documentation and forums. I am familiar with the processors they use. I looked at the source code and it looks reasonable.

 

Questions:

 

Is MSnS based on the same hardware as MS? Is custom firmware the only difference?

 

What hardware version of MS are you planning on using?

 

What firmware are you planning on using?

 

Do you have any example schematics of a MSnS running a wasted spark ignition?

 

Where would the crank/cam pos sensor(s) connect?

 

Where would the coil/ignitor connect?

 

Do you know of any web pages where it shows how a MSnS is connected to a signal source similar to the crank or cam pos sensors?

 

The more you guys can point me in the right direction the more helpful I can be. There is tons of info at www.msefi.com. Way too much for me to dig through in the time I have.

[JonOfScio]

oddcomp: we've been discussing using MSnS, not EDIS to run the car, so I wouldn't need that 36-1 or even any sort of x-1 to run the car. in fact, since I'd be using it on the cam rotation, I wouldn't even need a starting location. As all the signals that are sent should be TDC of each cylinder. (the way I've planned it)

 

MSnS is a seperate board from what I do believe, it's an add-on.

All of your questions are easily answered by cruising the site, it's not as hard as once believed.... check it out.

[JonOfScio]

well... MSnS is used for cars that already have a distributor.

 

So, it looks like I will need EDIS, and the 36-1 gear. But, not too worry... gonna send my crank pulley on out to shadow, who's thinking about making a template for a bolt on for those who want to undergo the MS thing.