In what world...
 

...does a megasquirt randomly stop running an engine?

Background: Mobius's built engine and MS3 basic from his wrecked '01 LS have been sitting in my garage while he's off in New Zealand. Plan is for him to buy my '01 LS when he gets back, preferably with his MS and engine installed, cause why shouldn't I enjoy his CNC head for a while.

So today I plug in his MS, run the map line to the back of the manifold, change his 32-2 trigger settings to 99-05, getting the basic ignition settings from the pnp pro VVT base map. I then told the MS I had a mazda coolant sensor, mazda air intake sensor, 265 injectors, and a narrow band.

To my slight surprise, it started up great. Cranked about 4-8 times, but it started and idled great. Throttle response was good too. Sat and idled for a few minutes while I made sure my wife had her cell, plugged in the scan gauge to rev's OBDII plug thingy, then went for a drive.

5.2 miles of near perfect* driving and it died**. Wife brought the stock ecu to me, it drove home fine.

*There was a SMALL bucking at constant speeds, I figured it was overly aggressive accel enrichments, and with no laptop I left it alone.

**first the battery light turned on, looked at the scan gauge and it said 12 volts. Then it went back to 14. Then it started bucking, generally running poorly, then 2 cylinders, then it died at a stop sign. This all happened in .6 miles.


Again, it runs fine on the stock ECU again. It just cranks and cranks on MS now, occasionally puffing, and very occasionally running on 2 cylinders. It's throwing a check engine light for sync error and/or VVT1 error.

Ideas?

a resistor fried inside? or even a board. perhaps the alt control board?
had this happen on a microsquirt that we were tuning on an impreza rs racecar.
no idea though, just guessing

I'd log the crank/cam sensors, they might be flakey when hot (but fine when cold) and the MS can't cope, but the OEM ecu can.

Bzzzzz. You loaded settings from a different ECU?

Just the rising/falling edge and 99-05 trigger wheel menu drop downs. Brought the latency to 0 as well. Not much else. I can get a full list, but the mspro map was never loaded, only referenced.

ok here's my ignition settings and a composite log. Again, I entered these by hand, I did not, at any time, load a MSpro map.

https://www.miataturbo.net/attachmen...ine=1442887046

https://www.miataturbo.net/attachmen...ine=1442887046

Are you taking a composite log while it's not wanting to sync up? Can you zoom in a bit so we can see the individual teeth on the main wheel also? From the bottom pic the teeth look connected at the top for some reason, may just be the resolution, I can't tell much though.

On my '99 I have the capture set to "rising edge". Seems to work great. Not sure if correct though....

The Basic MS3 requires a rising edge on the input capture, and a trigger angle of ~5.

Ok, tried that. Now I'm on my way to work.

Successfully made it to work, no lights aside from the immobilizer light blinking steadily away.

I was curious about the trigger offset, Richards original setting was 2*. If I lock it at 10*, should I have a mark at 10 and T? Or 10 and 20.

Lock timing at 10*. Marks should be at 10 and 20, adjust trigger angle until they are.