MicroSquirt.com read only forum (Jan.15,2018)

The new setup doesn't actually seem to have a missing tooth on it.

But it does have a missing tooth, as seen in the picture... I physically installed it:
Do you have any suggestions on what I should do?

Regards,
Adam

This is a close up of the trigger wheel from PE's website:
This is the guide we used to place it:

http://www.pe-ltd.com/Downloads%5CSuzuki%20App.pdf

Here's another Missing Tooth scope image, that also shows the cam pickup:

Excuse me, but you just have a crank trigger?
So you don't use VR2!
To get your set up to work with my Thunderace I used two diodes using 2.890 to get it to work.

To clarify, we are not using VR2in right now. We have an 12-1 wheel setup with no cam trigger. See the above posts for more details. I've attached the .msq that we're using now that doesn't work.

I am not sure what your diode solution will do for us -- we don't have a noise problem right now.

Here are two pictures of a bad signal output and a good one. This is exactly the same signal that the microsquirt sees, before any signal conditioning or polarity inversion.

We have a hunch that our VR signal has some problems but we're not sure how to fix them. Notice that our VR signal is not what you'd expect to see with a 12-1 wheel. The signal looks as if there are several missing teeth.

Oscilloscope capture of CURRENT engine signal while cranking:


We have an engine with an identical setup and the signal on it looks much nicer. The time scales on the X-axis are different though and the cranking speed may be different, so take that into consideration:

Osilloscope capture of WORKING engine signal while cranking:

We've been debugging this further, and just ran the engine without spark plugs in... to avoid what appears to be the engine slowing down during compression strokes. We have installed higher compression pistons in this engine, so this could be causing issues... plus it's not broken in. I've also positioned the vr sensor closer to the trigger wheel, and it has increased the voltage.

Here's a trace WITH spark plugs in: Here's a trace WITHOUT spark plugs in: Would you have any suggestions for making this work? I assume once the engine is broken in, the rpm wont vary as much during cranking, and it will approach the "without spark plugs" trace... but I would need the engine to run to do that, especially now that the trigger wheel is different from stock.

It seems that the timing between teeth isn't much different than the time at the missing tooth.
It would be nice to capture the non working vr signal with a more expanded scale

Here's a closeup of the VR signal WITH sparkplugs:

That's a big difference with plugs in and plugs out, and I just wonder if you could phase the missing tooth away from the compression strokes, by say rotating the 12-1 wheel on the crank or moving the sensor. I don't know what TachRef sees? but I imagine the processor is having a hard time with this.

24c wrote:That's a big difference with plugs in and plugs out, and I just wonder if you could phase the missing tooth away from the compression strokes, by say rotating the 12-1 wheel on the crank or moving the sensor. I don't know what TachRef sees? but I imagine the processor is having a hard time with this.

agreed. I could barely find the missing tooth by eye; I can't imagine the code is going to find it easily.