Trying to understand hall effect cam sensor setup on MS3Pro

[wndrllama103]

I'm having trouble understanding how the configuration of a 4-window hall effect cam sensor on the ms3pro.

I'm running a VW 1.8t with an OEM 4-window hall effect cam sensor; I have a cam fault (comes on a couple seconds after start) and I'm questioning my config.

The ignition log looks fine (I think?), but if I disconnect the cam sensor there is no effect on engine stability. So I'm pretty sure this is doing absolutely nothing.

I don't see anywhere to configure the ratio of cam to crank triggers in TunerStudio, so I don't know how the ecu could properly parse the data.
I was expecting that you would have to tell the ECU that you're expecting X number of cam signals per full engine cycle at a certain offset from the crank... or something like that.

All I can find in the ms3 docs is that "the timing is out of range". I don't know where that range is specified, or see how far out it is. And even that I think is related to VVT.

Thanks for any pointers/info.

[Matt Cramer]

You'll need to use Poll Level mode. See "Missing tooth crank wheel with irregular cam wheel" at this link.

https://www.ampefi.com/wp-content/uploa ... df#page=77

[wndrllama103]

You'll need to use Poll Level mode. See "Missing tooth crank wheel with irregular cam wheel" at this link.

https://www.ampefi.com/wp-content/uploa ... df#page=77

This seemed to do the trick.

I set poll level to low and to check at tooth #1 (found this as a suggestion on the internets), and the cam fault didn't show up anymore. That being said, the engine didn't run any differently.

Another thing that's odd, is that I don't see low-high transitions for the cam in my composite log; only ticks. Does this make sense? Is it just the style of wheel?

I'm also confused how this ran at all with the previous setup where the cam sensor was always in fault.

Is there some other configuration I should be checking?

[wndrllama103]

You'll need to use Poll Level mode. See "Missing tooth crank wheel with irregular cam wheel" at this link.

https://www.ampefi.com/wp-content/uploa ... df#page=77

So, I'm re-reading this, and I'm more confused.

"you can use the Poll Level feature to identify engine phase by finding a tooth that triggers on one engine rotation but not on another"

I looked at my composite log again and the cam triggers are the same on both engine rotations; 20 teeth in.

[wndrllama103]

Selecting "render including non-interrupt data" enabled me to see the high-low transitions. :: sigh ::

When looking at my composite log, I see a low->high transition at each crank trigger. There are two different window sizes, 20 teeth and 10.
So I guess I set the ecu to check at tooth 15? Not sure if it should be low or high; I could just brute force it and see which runs better I guess.

I'm still not understanding why it runs in poll mode with the current settings. Seem like it would be triggering on every crank rotation instead of every other.

[Paul_VR6]

Poll low tooth 5 is my go to for that wheel. I think on a vvt engine tooth 1 level will change with vvt on but it has been awhile.

Its entirely possible that it will run fine in this config as long as you have the engine phase id correct.

If you lose cam sync you get batch fuel and waste spark which probably runs ok. If its in cop/sequential it will run a *little* better. If it pics up cam on the wrong phase it will not run or run very poorly.