[PSIG]

Just to follow as you go; what were the results of the Missing Tooth decoder tests posted earlier?

[Hich]

Hi, thanks for following up.
I tested with "missing tooth" 2/1 which did not work. "basic distributer" and 2 cyl or 2-stroke seem to work (at least rpm in Tunerstudio looks ok now). However, I have not been able to get rid of the noise so far (shielded cables did not help) so the engine is not yet running. I'll keep you posted!
Best regards Karsten

[Chipboy]

Shielded cable with the sheath earthed one end only at speeduino?

[Hich]

Shielded cable with the sheath earthed one end only at speeduino?

Yes (almost), there are still some cm unshielded where the pickup cable comes out of the engine. I'll work on this during the weekend.

[LAV1000]

What type of VR sensor are you using ?
A 2 wire type ?
Or a 1 wire type which uses the engine ground for return ?

[Hich]

What type of VR sensor are you using ?
A 2 wire type ?
Or a 1 wire type which uses the engine ground for return ?

It is a 1 wire with engine ground.

[LAV1000]

It is a 1 wire with engine ground.

That's not the best option.
Might try a decent wire from engine ground (near VR sensor) to sensor ground on speeduino unit.
Or put some load (resistor parallel) on the VR sensor, this way sensor needs to dilliver a bit more power and smaller pulses, noise, wil be dissipated into the sensor.
Extra resistor is balacing act, resitor to low, sensor doesn't work at all, to high, stil noise.....

[Chipboy]

Shielded twisted pair is better, multistrand wire is required and the shield is not part of the circuit, earthed at speeduino, not engine.

By using the shield as you are it is no longer a shield and is picking up interference just as any normal wire will.

[Hich]

Thanks for the good suggestions. Hopefully, on the weekend I will have some time to work on this. I'll keep you posted!

[Hich]

I have now added a short wire from VR- to GND on the PCB, shielded cable with strand wire, shield only connected at the ECU and added 1k across VR+ and VR-(GND). Now it looks much better.
Every once in a while I get the engine running but it runs really poor, so I am thinking there is something wrong with the fuel amount.
I have now set 100ccm (the correct volume is 200ccm) 2 cyl, 1 injector, 1 squirt per cycle, and Two-stroke (instead of 4-stroke) and in Spark settings "Single channel".
This way, I am thinking I should get the correct amount of fuel for the 4-stroke 200ccm split into two squirts - one each 360 deg, and two ignition events per 720 deg, where only one will have an effect. Can anyone confirm my thinking or am I missing something? Will 2-stroke have any negative side effects elsewhere? As I don't have a CAM signal I thought it is better to distribute the fuel more evenly along the 720deg cycle.
This way I am getting 2.6ms for required fuel and 5.2ms base reference pulse width. Are these values reasonable? (Sounds a bit short for me).
Will "Enable per tooth timing" help in any way or should this rather be disabled?

Thanks a lot Karsten