[Mykk]

Working on a Speeduino installed on a basic distributor. Floating & Ground trigger, with v0.4.3 board (201905 firmware) Jumpered for Hall sensor & JP4 1k pullup also jumpered . Ignition coil controlled by speeduino with ign module.

Having trouble idling with trigger filtering off. Starts to misfire. Apply medium filter and it idles smooth as glass. However medium filtering doesn't like to crank, speeduino wont recognize a crank trigger until 10-20 seconds worth of cranking then once it see's the signal it fires up. With the filter turned off it cranks and fires up in just a few revolutions.

My personal VR sensor 60-2 BMW motor is similar, takes extended cranking to fire while filtering is on. Any way we can have the option to turn off filter while cranking but have it applied while running? Or have an "Enable filtering above RPM" option?

[NaBenzoate]

I would create a new post but i would be copying and pasting what was said above.

I can switch to a weak filter after start up and it idles and cruises much better. It will not start otherwise. V4.3c board running the Jeep2000 trigger.

[PSIG]

The need for software filters means an unstable or noisy signal. Generally, if one setting is not enough and the other "too good", then the next step is to eliminate the instability or noise that's requiring the filter.

Typically, stability is in hardware setup, and noise is not sourced in the sensor circuit, but subject to it. In other words, look elsewhere for the source of the noise. If you do a good job, there will be no need for any filters or juggling their effects.

[NaBenzoate]

My harness from the hall crank sensor has a shield around the entirety of it but is ungrounded. Aside from grounding the shielding what else do you recommend to eliminate the noise? The harness is on the opposite side of the coil and distributor in the engine bay.

[PSIG]

Hey, Sodium (you make whistles?) Without specifics of the circuit, I generally suggest to ground the shielding only at the ECM end, on a power (not sensor) ground. That could help, but keep in-mind, defending from noise is simpler if there is no noise to shield from. This again assumes it is a noise issue.

Noise also affects different sensors in different ways. Most of this is for Hall and optical (digital) sensors. VRs have an extra set of their own issues, and why we have many more threads about those. Keep hunting, and with the info below, even something unknown (like a missing or bad coil capacitor, which can make your coil location irrelevant ) can be found. When the source is too frustrating to find (with their knowledge and skills) is when users resort to defenses like shielding, instead of finding and killing the source. Get armed.

Diagnostics are easier with an oscilloscope so you can "see" the characteristics of the noise for clues, but it may be found other ways, such as I lightly described here. To apprentice a noise wizard with more brain matter (and he already did the work ), get comfy and read this.

Grounds are the bane of things electronic, and will be the source of problems more often than not. Without much more info or hands-on, we have to go with "more often". Good luck!

[theonewithin]

Ensure correct trigger edge is selected for the conditioner you are using also.

It is important.

Wiki has details.