MM9495 for use with a 1990

[thelaughingman]

Hello MXCT

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. I thought i'd make a new thread rather than clog the MegaSquirt thread.

So to begin with I have a MM9495 ECU these supposedly can be used with the 1990 models if repinned to the 94 - 95 model spec.

My MX5 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:

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!

[93_Clubman]

Couple of things which you may or may not be aware of:
There are some pinout differences between domestic markets, ie ADM, JDM & USDM, so it can be important where you've sourced your info from & which domestic market your NA6 is, although ADM & JDM were said to be very similar in many ways, but differences were noted with USDM.

That said, have you seen this:

http://forum.miata.net/vb/showthread.php?t=226162&page=10

I may have something that is specifically ADM which might help, so will post here if I can find it.

[thelaughingman]

Ah thanks for that i wasn't aware that there were any differences.

Any help would be appreciated.

[timk]

You have identified the batch fired injection, you may be able to hook up just two injector channels and configure it within the MSPNP to be batch fired if you don't want to rewire the thing.

The TPS will be a problem as it is a simple switch on the 1.6 not a potentiometer - I used a BMW TPS (part number 0280120402, I pulled it from what I think was an auto 528i) and it was a direct mechanical fit into the 1.6 throttle body, the wiring plug was different though. Pins 1-3 were +5V, ground, signal.

[93_Clubman]

PM'd

[thelaughingman]

You have identified the batch fired injection, you may be able to hook up just two injector channels and configure it within the MSPNP to be batch fired if you don't want to rewire the thing.

From what i can see it only has sequential, worst case scenario what would have to convert? Just the injector harness or the whole injection system?

The TPS will be a problem as it is a simple switch on the 1.6 not a potentiometer - I used a BMW TPS (part number 0280120402, I pulled it from what I think was an auto 528i) and it was a direct mechanical fit into the 1.6 throttle body, the wiring plug was different though. Pins 1-3 were +5V, ground, signal.

Would it be better/easier to use a 1.8 throttle body?

Timk would you be able to do a write up?

[timk]

1.8 throttle body is larger and won't bolt up to the 1.6 intake manifold.

If our 1.6 has batch fired injectors you may be able to use the injection loom from a 1.8, make sure you check before going to any effort!

I wish I could help but I don't have my NA anymore.

[thelaughingman]

If our 1.6 has batch fired injectors you may be able to use the injection loom from a 1.8, make sure you check before going to any effort!

So i followed up on this to see if i would have to change everything over and the response from DIYAuto..

Depending if you have a gen 1 or gen 2 MSPNP, this function may be disabled on the main board its self. You can also set the ECU for unlimited injection with your Tuner Studio program for batch injection. The 90-93 miata was setup for bank fueling, and I recommend firing the injectors in this way.

The question now is am i able to just leave the injector wiring alone and change the settings in the ECU without issue OR splice 2 extra wires for the 1&3 and 2&4 injectors and repin them into the other places on the harness connector.

Thoughts?

[93_Clubman]

Re TPS, post that might be of interest:
How to: Cheapy Variable TPS for Megasquirt:
viewtopic.php?f=81&t=60610
There have also been a couple of similar how to TPS posts in the past on here.

[thelaughingman]

thanks for the help guys!

[datfreak]

Hey, did you get this working well?
I'm getting a MM9495 soon- also going into a na6.
thanks for any info

[smy0003]

I emailed diyautotune about using a 90-93 MS2 in a 95.
They said I would have to use an na6 wiring harness.

Sent from my GT-I9505 using Tapatalk

[datfreak]

Thanks for the info. I hope it won't be too hard to get working.
The tps pins look different so maybe will have to switch them around..
I prob should have waited until a na6 megasqiirt came up on the forums.

[smy0003]

There's an MS2 for an na6 going on here

Sent from my GT-I9505 using Tapatalk

[datfreak]

There's an MS2 for an na6 going on here

Sent from my GT-I9505 using Tapatalk

I saw this mspnp but its past my budget.


Should I start a new thread in this area for this megasquirt install? Or just ask q's here?

so tonight Ive :

removed the ig fuse-
plugged in the mspnp
unplugged the tps
loaded the na6 maps for fuel and ignition from the diy website.
(Aussie driver maps from http://www.diyautotune.com/tech_articles/how_to_megasquirt_your_mazda_miata.htm)
hooked up the vac line

and it started and runs fine.

ive since done the timing.


It does not run with out the MAF plugged in, so I think the fuel pump isn't being triggered by the ecu.
Anyone know how to set this up? is the na8 different from na6 for the fuel pump starter trigger perhaps? Was thinking of joining 1c and 2t so the ecu joins the relay

I'm going to drive her in to work tomorrow- so hopefully all is well in the megasquirt department

Ive also bought a lc-2 wideband sensor and will wire this up soon.