RemoteMX5

Well some of you might have seen my post about the FMU in the DIY forum. Well I ditched the idea, too much of a hassle and money for something not reliable enough.

Anyways, I always wanted to get into the MS game so I decided now is a good time as ever. Especially since I own a 2005, and not many tuning options for it out there that don't cost an arm and a leg.

So I bought my self MegaSquirt-I Programmable EFI System PCB3.0, I'm pretty good with electronics and soldering, and have the understanding of it. So I figured why not.

I chose the MegaSquirt-I PCB3.0 cause it will do what I need it to do right now is control my fueling needs, and also has room to upgrade later on to timing control and all.

So I was thinking of running this unit parallel to my stock ecu, where I would cut the feed and ground injector wires from the stuck ecu and run them into the MS.

So my question is. The minute I cut the wires from the ECU, will it go haywire and throw a bitch fit? And would I be able to use the build in map sensor thats inter graded on the board?

Now I know that at that point the Maf is useless but I cant disconnected cause then the ecu will for sure go hay wire, how do I go about solving that problem?

Thats pretty much it, this is also on a 2005 Miata, only ecu wiring diagrams Iv seen so far only go up to 00, so I'm not sure if they are the same or if there is a pin out diagram out there for an 05, but I am willing to do a small write up as I go along.

And suggestion and inputs are greatly appreciated, thanks.
Mike

patsmx5

iTrader: (16)

The stock ECU will never know your MS is controlling fuel or spark if you just cut the output wires and splice in the MS. Not sure about removing the MAF sensor. I still have my stock ecu in place, but I got a constant CEL now from removing one of the oxygen sensors. What are you worried about by "go haywire and throw a bitch fit"? It will throw a CEL probably if you remove the MAF sensor. You can run the MS in parallel and use the stock sensors, I'm doing it and so are a few others.

Braineack

iTrader: (62)

have you seen my write up? same rules will apply...just get yourself a 90-97 CAS. leave the MAF in place, it's hardly any restriction anywhere.

RemoteMX5

Wow guys awesome fast responses.

But yeah thats excellent news about it not even knowing about the injectors. And I wasn't worrying about the ECU knowing that the MS is controlling the the Fuel heh. I know that all the ecu does for injectors is grounds them on and off. I just didn't know if it receives any input from them. But I guess it doesnt so thats good ..

As for a bitch fit I pretty much meant the cell heh, I can deal with a the cell on Until I go for emissions then Il just plug it in and cell is gone ...

As for timing, I have a J&S safeguard which has proven it self on my other projects so Il just go with that for right now ..

As for the ECU pin out diagram, can I use the '00 pin out or is the '05 much different any one know?

And Im about to check out your write up right now Thanks.

Braineack

iTrader: (62)

im sure the pinout is different:

http://www.fastforwardsuperchargers....5-ECU-Pins.jpg

if anything you wanna go by the colors...typically mazda doesn't change them.


as far as timing, MS will have full control...if anything, use it solely as a knock detector, or figure a way to have MS retard the timing using it's outputs.

RemoteMX5

Whoa excellent dude thanks a ton for that Diagram. I think all my questions have been answered heh. As for MS controlling my timing. Right now I'm just going to have control my fuel and learn that inside and out, and then move onto timing control.

Im the type of person where I learn quickly, but I like to get things working one at a time if possible ...

cjernigan

iTrader: (13)

Buy a boomslang harness when doing this. It will keep you from destroying your stock harness making this a 100% reversible setup if you decide you don't like it. You won't have any issues though, MS is great.
Compy is running MS on his 01 or 02 w/e it is.

paul

iTrader: (21)

it's 23C, does the year really matter?


any idea if that pinout is the same for the MSMs?

compy

Indeed I is.

(2001)

cjernigan

iTrader: (13)

The MSMs don't have VVT and all that do they? If not i doubt the pinout is the same then.

paul

iTrader: (21)

nice sig compy "My worlds on fire."

i guess your hemorrhoids are flaring up from all that ---- sex

paul

iTrader: (21)

true

compy

Yeah tell your mom I said sorry about that.