Megasquirt owners thread

[Red_Bullet]

While I haven't played around a great deal with injection timing yet (although my table isn't 360 across the map), unburnt fuel will read leaner not richer since o2 sensors read o2 not fuel.

Thanks Bartmanftw, that's a valuable input. I've been doing some calculations regarding injector dead time. To cut a long story short, IF it takes .8 m/s for an injector to stop spraying after the ECU turns it off then that .8ms accounts for 35 degrees of crank revolution at 7000 RPM. I'm going to load up an injector timing table based on this. Starting at bottom left of the table 370 deg sloping up to top right 405 (370+35)

[Red_Bullet]

Getting close now.

best yet scatter plot by Keith Wade, on Flickr

[Red_Bullet]

Using Megalog Viewer HD (MLV HD)

This is worth a look:

https://www.youtube.com/watch?v=N7zqmWfblxg

[Red_Bullet]

Some more stuff. I have too much time on my hands at present!

I have had the wrong dead time in my MSQ for nearly 3 years. RX8 injectors. I had dead time set at 1mS. When I changed it to a "better" value of .8mS idle would go stupid lean. Not wanting to retune the whole VE, I had until now decided to just leave it at 1mS and live with it.

BUT...

You can use this spreadsheet that I've designed to recalibrate the VE table. I tried it, seems to work fine at idle, (the worst scenario, low pulse width). I still have to VEAL higher Pulse widths, but I think they should be pretty close hopefully. Use at your own risk, and if you don't understand why you might need it then don't use it.

https://drive.google.com/open?id=1lTiwZ ... uT4rBK2EhD

[Red_Bullet]

Look here for further MS info:
http://www.mx5cartalk.com/forum/viewtopic.php?f=81&t=76411

[Red_Bullet]

Interesting youtube video on tuning.
https://www.youtube.com/watch?v=6bkDKqoGSdU

[rossint]

I need to upgrade the firmware on my MSPNP2 from 3.3.0 to the latest 3.4 firmware to get the ECU talking to my laptimer/data logger.
Does anyone know if there will be issues reloading my current tune after the upgrade?

[ManiacLachy]

I haven't had any issues upgrading firmware on my MSPNP-Pro, but make sure you do all the backups before hand!

[rossint]

Thanks Lachy, looks pretty straight forward to do and the release notes say there’s only a couple of differences between the 2 versions.

[rossint]

I have a MSPNP2 MM9095 V1.3 that I'm trying to enable CANBUS on.
I've identified where it needs to be wired to, to get to the options port but I'm struggling to find the JS6 and JS8 jumpers.
Any help would be appreciated.

[StanTheMan]

So I don't have any spark.

BP4W into NA6 chassis conversion.
car has run. both with old spark system as well as the new system.
I'm unsure about the cops.They are off a Toyota Supra. The wiring is correct. Car has run in the past.With the current wiring & COPS then stopped

I have replaced sensors
I have added the 36-2 trigger wheel
I have added the cam sensor.
Ive added the Nb8A cam sprockets
If the wiring was wrong on the sensors I assume I would just get a line?
Ive changed the setting in Mega-squirt 2 PnP to Miata 36-2 in ignition settings
Ive swapped around falling edge to rising edge in case I had he sensor incorrectly wired

but I'm getting the wrong signal here
pic of offending signal

Signals.JPG

and its not starting

[Aiming Faster]

Hi all. I have a 'MS3 Basic' and was making some adjustments (successfully), then set up alternator control.... no spark.
After a bit of checking, attempted to reburn setting, but could not connect to ECU.
Opened the box and found a blown fuse (the fuse may be for O2 sensor power), but still no communication.
Car runs on original ECU (rich but reasonably), so I need advice on what to check next.
Tried another computer, cables-USB and Serial... no communication.
Ideas??

[ManiacLachy]

I'd get in touch with Reverent who makes the MS3 Basic, MS Labs is the company I think. He'll be able to advise you better, but it sounds like you'll need to repair the board, which might mean sending it back to him. You might be able to re-wire the fuse, but finding the cause of it blowing might be a bit harder.

Even if you bought it second hand I'm sure he'll still offer some level of support.

[Red_Bullet]

Hi all. I have a 'MS3 Basic' and was making some adjustments (successfully), then set up alternator control.... no spark.
After a bit of checking, attempted to reburn setting, but could not connect to ECU.
Opened the box and found a blown fuse (the fuse may be for O2 sensor power), but still no communication.
Car runs on original ECU (rich but reasonably), so I need advice on what to check next.
Tried another computer, cables-USB and Serial... no communication.
Ideas??

Info on including the manual on the MS3 pro circuit board can be found here:

https://www.diyautotune.com/product/ms3-pro-module/

On the MS3 pro board itself there are two small surface mount fuses F1 and F2. One of them IIRC is on the 12 volt supply in. If this is blown then the ECU will not power up. The other fuse protects the 5 volt supply to sensors such as TPS and so on. You could most likely get the fuses from Jaycar.

From the manual:

3.5.1 Changing the fuses
The MS3-Pro uses two replaceable fuses. The F1 fuse protects the main input; if it blows, the entire
MS3-Pro will shut down. The F2 fuse protects just the TPS reference voltage output. If it fails, you
lose the reference voltage in the wiring harness, but all internal operation in the MS3-Pro will continue
as normal. If you have a fuse blow, please check to be sure there are no short circuits that may have
caused the problem. (Note that a short circuit in VREF can cause either fuse to blow.)
To remove the fuses, use a needle nose pliers to pull the fuse out of its holder and press a new
fuse (available from DIYAutoTune.com) into its place.
DIYAutoTune.com

[Aiming Faster]

Thanks Red Bullet, it's a 'Basic' model, not a 'Pro', so quite a different beast. I did have another look at the circuit boards in it, no signs of a problem. Powered up to see the 12v and 5v LEDs operate when the box is open.
Any more suggestions??