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

I haven't read a post here or MS2 forums that have solved my VR input noise issue.

My Set Up
2002 Yamaha R1
microsquirt v2 board
Bosch 211 igniter for COP
16-1 crank wheel VR input
1 tooth cam hall sensor input
Optima red top batt
11ft of 6 ga starter wire

A picture of my 16-1 crank wheel:


It is oriented so that TDC of Cyl 1 occurs first tooth after missing tooth. The missing tooth synchronizes nicely with slowing rpm from the compression of the motor to make a visual distinction. See oscope trace below.
+/- 2.1V amplitude.
Compression tooth to tooth gap 22.5ms.
Regular tooth to tooth gap 7.75ms.
Missing tooth gap 45.5ms.

However I am getting significant noise from the starter (If the engine eventually catches and starts it runs fine.)



This leads to false triggers and poor crank sync.




I tried adding a 10k Ohm pot on the VR1+ but it didn't help the noise.
VR2+ is attached to the hall effect on the cam sensor.
VR1- and VR2- are on same pin 33.
6ga batt ground direct to engine block 10ga ground from engine block to sensor ground bus.
Starter rpm in 250-350rpm plenty CCA from red top battery.
Measured VR sensor gap (stock setting) to be .15mm

I'm having a hell of time getting it to start, please any suggestions are appreciated. I was thinking of ordering a Hamlin hall effect if this starter noise is incurable.

Ran 100k pot inline VR1+

10k = didn't work at all
20k = showed a little promise
33k = significant starter noise reduction and rock steady cranking sync

evanevan wrote:Ran 100k pot inline VR1+

10k = didn't work at all
20k = showed a little promise
33k = significant starter noise reduction and rock steady cranking sync

That's useful information, as I only ever tried 10K previously, before messing with diodes. What was your peak to peak voltage at cranking, before and after?

For what it's worth, my microsquirt harness had the ground and signal pins reversed, so the + was free to pick up whatever induced noise it could. While fixing that, I decided to switch to a 3 conductor shielded cable. Now: 1 condutor = plus = pin 32... 2nd conductor = minus = pin 33 ...3rd conductor = outer shielded to the system ground external to uS.
Carl