MiataMath

I have installed my MS in mine. But it's controlling nothing at the moment.

I have yet to install the GM coolant sensor has I had no luck in using the stock Miata one. Even using Easytherm and the data found on msefi.com for the Mazda coolant sensor.

(To install the GM sensor.. I bought a 3-4 inch long 1/2"ID pipe and I went to a garage to have them weld on a Bung in the middle of it, I'll cut one of the heater hose in half and insert the pipe with the sensor in)

As soon as the sensor is installed, I'll take control of the injector and see how well this ECU is behaving.

I splice into the stock harness for all sensor except the addiotional temp sensor that I ran a wire up to the engine. :
And all my reading are fine: Rpm (using the DSM mod on DIYauto webpage). stock O2 sensor. tps (I have a 96 so TPS is a 0-5v one, unlike 1.6L) IAT (using GM sensor wrapped to air filter), MAP.. etc.

I'll update this thread when I have more progress.


Oh: I had a check engine light go on as I did a mistake wiring the RPM signal. I was connecting both the white and yellow wire to my MS but the stock ECU didn't like it.. throwing a MIL about misfire. I disconnected the yellow one and left the white one and it fire right up. I guess I will only need to connect both when I take control over the ignition.

Jefe

iTrader: (7)

Just curious, how far from the US/VT border are you?

MiataMath

About 15-20 min from the Lacolle border.

Al Hounos

How are you reading RPM?
Also, do you play LFS?

MiataMath

I'm reading the RPM using the white cable from the stock harness going in Pin 24 of MS.

I had to made sure to set the constant to 4cyl because it was reading half of the rpm with the default V8 setting :gay:


I'm officially doing the injection tomorrow morning. I'll update this thread with the wiring diagram I use and the Pinout I used.



PS: I do play LFS under the same nick name Actuallly.. Core_MiataMath.

Are you too?

MiataMath

It is alive!!!

I got the fueling part up and running.

It is far from being tuned out but the car run nice and doesn't sputter. I had a slight problem with getting up to speed from a slow start in 1st gear. I had to tweak the MAP a bit for the High KPA low RPM value and the AE value to get rid of the hesitation/sluggish revving.

I was confident enough to do a few WOT throttle pass up to 6k but I stopped there as the O2 was starting to get lean. Will have to tune this out too.

I have yet to experiment any cold start so I can't comment.


Stay tuned for more details!

Al Hounos

If you need cold start settings let me know. What code version are you running? I say this because you might as well upgrade to 29+ now because my VE did not transfer well from 24s. So I'm having to redo most of my map.

PS I raced as AL. Not so much anymore, too many Formula car only servers.

medisyn

Awesome miatamath! Did you build to buy prebuilt?

MiataMath

I bought it unassembled from DIYauto and built it myself.

Al, I would appreciate if I could take a peak at your setting.

I'm back from a 2-3 hours tuning sessions. I think I got a good base map but time will tell.. I still have that slight slight hesitation just off idle.. Probably the accell setting need more attention.

I'm running the version 24 for now.. What's different on 29?

Edit: Good news for the OBDII crew out there.. the stock ECU doesn't care if the injector are there or not. I have no CEL at all

Al Hounos

Ok here it is. This has only been tested down to about 45degrees. The setup is pretty mangled because of the switching from 24 to 29, but the cranking values stayed the same.

I say upgrade before you spend a lot of time tuning, because you will be stuck with 24s if you want to keep your msq and not have to redo it. But if you've got it running well, don't worry about it I guess.

medisyn

Going into building the MS what was your level of experiance? I am wondering if I am up to building the thing. The only time I have sodered is to make some cables using cat 5 for my home theature setup..

cburkart

Why not buy the stim kit first? It's ~$40 from DIYautotune. Get your feet wet building that and then you'll be more well prepared to the full MS kit. I think Jerry suggests this as a good way to get started.

MiataMath

I had some welding experience back from a short electronic class I took a couple of year ago. I would say that I'm ok with the Iron, doing nice weld. But after a few weld anyway.. you would it get used to it.

The assembly in itself went out fine. But man.. it was more time consuming that I tought. I didn't not count the time it took me but a minimum of 10 hour at least. With all the reading.. finding which mod to do for the car.. doing the mod.. testing the board, fixing the small assembly error you might do. etc etc.

It was a really nice learning experience... But I'm not sure if I should have bought it assembled It would have save me a lot of time. I guess I can brag that I really build my ECU from the ground up.. LOL..

If you are not in a rush to have it working.. only doing it part time on the week-end, it can be fun.


Thank AL, I think I will upgrade to the 029 version.. I just read that you can RPM base AE in that version.. it might help my tuning. I don't really have anything special so far in 024 apart from the VE table that I can export and import back.

MiataMath

My tune is getting better and better.

This morning, it was 23F and my car started on the 2nd attempt. I then slightly adjusted the value afterward. I'm pretty sure it did not start right away because I didn`t wait for the fuel pump priming pulse :gay: Anyway, it promptly went to fast idle once started (IAC controlled by stock ECU) and after a minute, I just drove away.

My accel setting is getting better and better. I had a small stumble when hitting the throttle from idle in neutral at first. But I think I pretty much nailed it down by using the RPM base accel and a fairly rich (3.5ms) and short shot of fuel (0.2sec) for the low rpm Bin. I might retune that after a few more days of trial and error.

I did 240 miles out of my first tank of gaz doing bunch of WOT run and tuning fuel and stuff. Not too bad actually I normally get 260 before filling up.

MS is nice!!

Jefe

iTrader: (7)

So you must be near Parc Safari?

The Lacolle/Champlain border is ~ 45 min from my house.

MiataMath

After a little road trip to get some fuel this week-end.. I think I under-estimate the time it take lol.. More like 30 min..

But anyway.. I live at St-Jean-Sur-Richelieu.. Not really close to parc safari.

Jefe

iTrader: (7)

Distance: 58.9 mi (about 1 hour 35 mins)
My kids like Parc Safari.. I think it smells funny...

MiataMath

I guess I should update my story a bit.

It's been near 700 miles now and it is still going strong.

I'm still adjusting my cold start.. 15F so far and it started.... on the 2nd try.. Not too shaby.

My AE need some more work but that's not really affecting drivability.

I did a few highway autotune run going back and forth to work. and smoothed up the VE Bin a bit afterward.

Gas economy is not aasss great as I expected.. but I'm doing LOT of stop-go rush hour traffic. getting around 24 mpg.. ... It was a bit better on the stock ECU but not by much.

Ignition will be next.. but not before spring and a bit more money flowing.. After reading a topic on Miata.Net I'm afraid to blow up the stock 1.8L coil. So I'm planning to either go COP or buy some cheap GM coil and wire them instead.

MiataMath

Got 27 mpg average on that tank on my daily rush hour commute. I leaned out my VE table a bit and it seem to be nice improvment.


I also snap a picture of the additional coolant sensor I installed if someone want to give this a try. Don't mind the broken dipstick..
lol

MiataMath

It's been over 3000 miles now and the megasquirt is still running great with no major hiccup. Still only controlling fuel.

The car is still use as a daily commuter so it proves its reliability.

I only came across some small issue when the intake air temperature was reading high. The nice hot weather we have lately brought that problem up. What happen is that MS lean the mixture out when IAT read high.
So, as the underhood temperature raise, the leaner the idle is.
I used the air density correction in MS'n'S to enrich the mixture at idle when IAT get really high. It seems to work rather well actually.


Best Regards!

Math