Tachref sees nothing, but TunerStudio sees RPM?

[ScramblerXLE]

Hello!

So I finally got an 18-1 tooth trigger wheel installed for my project and a VR sensor off a Yamaha YFZ450. (Bench test setup, simply cases, a crank to spin by hand, the trigger wheel, and a VR sensor) I fought with it for a while Monday night, but was unable to get a signal to show up in Tachref. I tried again last night and noticed something interesting. Still seeing nothing in Tachref, I went back and re-read the info page on it to see if I was missing something.

I noticed the part where it said that if I didn’t start cranking within 2s, the test would halt and I would have to start it manually again. To test that Tachref was working correctly, I started the test and did nothing. Sure enough, 2s later, the test halted. Then I started spinning the crank and hit start again. This time, despite not drawing anything, as long as I spun the crank, the test continued, and it stopped once I stopped turning the crank, exactly as it should have.

Clearly, the Microsquirt was seeing something, I’m not just sure what as Tachref won't draw anything. So I re-flashed and loaded 3.830 and opened tuner studio, set up all the appropriate trigger wheel info, and started cranking by hand. TunerStudio registered the RPM like nothing was wrong! Cranking by hand, varying the speed, I could get it to see anything from around 70 RPM up to around 300 before I couldn't spin it any quicker. It certainly seems to be working correctly in TunerStudio.

I'm certainly happy to be making some progress. It seems from what I’m seeing in TunerStudio, that I may have a viable crank signal, now I just need to find a suitable VR sensor that will fit under the side cover… Any idea why I can’t see anything in Tachref? I tried a search but didn't see where this had been discussed in the past.

Thanks!

-Walt

[24c]

Hi Walt,

Don't worry about TachRef, as I always found TachRef quite flaky, but I was using a cased v1 & v2 MicroSquirt, but I hope you're using a v3 Microsquirt. It's much better.

The fact that you are seeing RPMs in Tunerstudio varying between 70-300 is good, but as you said you've made a dummy crank in a set of crankcases for bench testing, so why not stick a lock nut on the shaft, and use a cordless drill and socket to power it? To stop the conrod flailing around if it's fitted, I've used an elastic bungie cord suspended off a shelf!!

A good cordless drill will do 0-700, and about 1700 or more rpm in 2nd gear. So you can do a simulated cranking, idle and fast idle setting.

Next thing, I'd do is add some 12V LEDs as a dummy ignition and injector indicators, and visually check that you're getting sparks & fuel.

Mike