Converting a MM9495 for use with a 1990
 

Hello TM.net

I've been searching the web for the last two days trying to work out how to go about doing this without much luck. If anyone can help me with this issue i would appreciate it a lot.

So to begin with I have a MM9495 ECU these supposedly can only be used with the 94 - 95 models.
My MX5 (or miata) is a 1990 1.6ltr Manual, no A/c No Power Steering - this may or may not make a difference

I've looked at the pin outs and i've come up with this picture below:
https://www.miataturbo.net/attachmen...ine=1385422893

Now i have a few questions on how to repin this so i can get this to work on my 1990.

Also forgive me in advance as electronics aren't my forte.

1K
On the 95 model what does this data link do? Is it the same as the 1K on the 1990 (Igntion adjustment connector)

1L
On the 95 this is the radiator relay, to which wire should i splice this into on the 1990 harness

1M
How should i connect the VSS sensor again to which would i splice?

2F
Is this needed? or can i just disable in the ECU to make things easier

2H & 2R
How would i connect these? Would i have to change the injection system?

2J
Am i right in thinking that i would just have to repin/splice this to the 1R?

2N
Heated o2 sensor Vs Standard o2 sensor do i have to change the o2 sensors?
i'll also be using a LC1 wideband if that makes a difference

2T
Where would i connect this too?

2U 2V 2Y 2Z
These are all per injector 1-4 respectivly. where as on the 1990 model 2U does injectors 1&3 and 2V does injectors 2&4
And 2Z is used by the Transmission control model

So please tell me what i need to do to get this to work. This is not my daily driver so it can sit in pieces while i get things done.

Thanks in advance!

I'm guessing the MM9495 is the same as the MSPNP MM9495? If so, this is a factory made mother board, right?
Curious, did you switch cars, engines or are you just trying to fit a 1.8 ecu in a 1.6 car?

More knowledgeable folks can jump in, but my 2 cents is to find a MSPNP MM9093 box. Save a lot of headaches. If you had a plain MS1, 2 or 3, with the 3.0 board you could change everything you wanted and more. I am not at all sure of the differences between the MM9093 and the MM9495, but looking inside my 1.6 box the main processor and daughter board are both labeled as 9093 so it seems you may need another daughter board and processor. The rest of the thing seems to be a MegaSquirt with a 3.57 board. Maybe the processor could be re-flashed with the right firmware and all you would need is the daughter board.

Matt can surely tell you, but seems to me even if its doable it may be too much work to cobble together what you would need to be worthwhile. Only thing I've ever done to my MSPNP for the 1.6 was to convert to a variable TPS and this was done with directions from Matt at DIY.

Good luck with the thing - curious to see what anyone else thinks of your questions.

there's only a few wires you need to move tit for tat. Since it's a MSPNP box that makes it a little tricky since the wiring harness is actually just a daughterboard specifically designed for the model year.

It will actually run if you just plug it in and use it but you'll never be able to hook up a vtps without hacking up the wiring a bit and the fan control will not work, but that's fine since you have a thermoswitch.

So i can just take out my stock ecu and connect it up and it will work?

any suggestions so i can get it tuned better

so long as you unplug the stock tps, yes I think so.

oh yeah, and you'll have to do something about the fuel pump too.

It comes out 2T on the 94-95, and that's an unused spot on the 90-93. So you'll need to either jump f/p and ground in the diagnostics box to always run the f/P or keep the AFM installed so it can trigger it.

Ok thanks so much!

Ill let you all know how i go and i'll try to do a write up as well.

Great news everyone :D

So i finally got around to testing the megasquirt - removed my standard ecu connected the megasquirt turned on the car and bang works the car hunts from 800rpm to 1000rpm going up and then down and the fueling is out but it runs the car - this means i wont have to change anywires i'll just adjust via software!

im very happy

Well shut my mouth and call me dumbo! Glad you got it going.

Well wouldn't say got it going quite yet i have to get the cable for tuning and a laptop (my wife wont let me use hers haha) but baby steps