Want to go Parallel why shouldn't I?
 

I going to get my ms2 built shortly. It will cost me the same to go parallel or stand alone.

I want to go parallel for stock idle, A/C.


Seeing how parallel will alow spark and fuel to be tuned is there any reason to go stand alone?

Setup will be

FM2 kit
8 psi
Track Speed Engineering radiator
big oil cooler

MS2 standalone did a better job of idle control than the stock computer did in parallel in my 99. Don't know what year car you have, but it looks like the NB stock computer varied ignition timing as part of the idle control scheme more so than varying duty cycle on the idle valve. Allowing the stock computer to control idle valve without allowing it to control spark doesn't work as well as setting up the MS2 standalone.

This is a noob question I am sure...

Is it still considered a parallel install if you have the MS taking control of IDLE, AC, Spark, Fuel, etc - leaving the stock computer as basically an "observer" of the whole thing?

At what point does chopping off the stock (2001 for example) ECU's ability to make changes cause it to throw OBDII fits?

I know I am adding a lot of complexity here, but I want to retain the function of my immobilizer in some way but still have the MSIII doing as much as possible.

The stock ecu still thinks it's doing something, so it stays fairly happy unless you're causing misfires or something.

what year miata is this for? if idle and a/c are the only concern, then I would still to standalone...if emissions are the reason, then yeah.

I've been saying this for years, I had this problem with my parallel MS1. It was brilliant in fuel-only mode, however when I switched to spark control as well, it was sad. I switched to MS2 standalone and never looked back.

The stock ECU doesnt do an exceptional job at controlling idle once youve put a turbo on.
I had lots of idle dipping problems under braking. Still no clue what exactly was happening...

removing any of the normal sensors completely will throw codes. sharing them wont.

how about stock ECU does fuel pump only.

Perfect! The answer was staring me in the face.

Also, Braineak is a perceptive dude. That is all I am saying...

Not to threadjack, but my car doesn't even have a turbo on it yet, so this is all for educational purposes of course. (in my case)

go on...


:brain:

you may want to check that the immobilizer DOES indeed shut down the fuel pump.

But even if it does not shut down the pump, is there a signal that it DOES keep powered when the proper key is inserted? If that is the case, I should be able to rob that signal to power a relay on the fuel pump. No?

At work and without looking at my references this is all hypothetical BS though... Maybe I need to get a non immobilizer key cut for testing purposes.

EDIT: Webernets is saying that it controls ignition? More research needed.

the immobilizer is mated with a specific ECU. it doesn't turn something on but rather enables the ECU to turn something on.

Well, that's what I mean. But what exactly is it (the ECU) turning on? The ECU itself?