VR sensor input noise!! Should I switch to Hall Sensor?

[evanevan]

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.

[evanevan]

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

[24c]

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?

[DblTrbl]

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