# What type of Hall sensor do I have? AGG/2E engine with micro/megasquirt.



## o.g.johnson (Jun 1, 2010)

Hi folks, I've just joined on here, looking for some advice if anyone can help  

I'm in the middle of installing microsquirt to control ignition on a mk2 golf, currently running K-jetronic/CIS with a mechanical distributor. I'll be fitting a fixed distributor from a 2E engine (four window rotor for Hall sender), plus there's already the 60-2 toothed wheel on the crank. I'd rather use the crank signal, and just let the distributor take care of distributing the spark, but I'm flexible on this. Trouble is, I'm having some bother finding out exactly how to wire the Hall signal into the ECU. 

Both distributor and crank sensors on this car are Hall devices, not variable reluctor, seems to be the general consensus. 

Microsquirt has the VR inputs (which I won't be using), and the optoin +ive and -ive inputs which are appropriate for a Hall device. Apparently Hall sensors can be naturally 'high' or naturally 'low', and this decides whether the optoin input should be +ive or -ve. 

Which of the optoin inputs should I use with either of these sensors? Is there a way I can test the Hall sensor type with a volt meter? 

Cheers guys


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## o.g.johnson (Jun 1, 2010)

Sort of answered my own question here, but I'll put up some pics in case anyone's interested. 

Hall sensor facing metal, 9V showing: 










Hall sensor facing window, 0.1V showing: 










Distributor set at firing point, mark on body lined up with rotor arm, edge of window just passing Hall sensor: 










So for this distributor (VW/Audi part no. 037 905 205 J, Bosch part no. 0 237 520 048, from VW engine code 2E) at least, spark trigger would be on the transition from low to high signal, ie: rising edge. 

Hall sensor part number (Bosch) is: 1 230 329 062


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## need_a_VR6 (May 19, 1999)

Good work. All the VW distributors I've used I've wired low-high, with a trigger angle of ~60deg. 

With Microsquirt or MS2/3 it's not as important as you can select the input edge in software.


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## o.g.johnson (Jun 1, 2010)

Cheers  

So I think I'm correct in thinking that I can go ahead and connect the Hall signal to OPTOIN+, and OPTOIN- to sensor ground. If the Hall signal had gone from high to low at the trigger point I'd have connected them the other way round.


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## Prof315 (Jan 5, 2009)

If you have a 60-2 tooth wheel on the crankshaft use it. You will be much more accurate on your timing as that signal will have 15 times the resolution of a 4 window hall on the distributor. And that doesn't take into account gear slop and timing belt deflection.


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## o.g.johnson (Jun 1, 2010)

Ideally yes, you're right Prof. To avoid timing scatter this was my original plan but just trying to get my head round it at the moment, as it seems a lot more compliated than using the dizzy. The crank sensor is Hall as well on this model but I haven't worked out how the microsquirt reads the 60-2 trigger wheel yet. More work is needed on my part.


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## Prof315 (Jan 5, 2009)

Hook it up the same way, but instead of trigger return (or whatever) as your tach input choose toothed wheel. Then in trigger wheel settings use single wheel with missing teeth,60 teeth, 2 missing teeth and 78 degrees for tooth # 1 angle (Every VW with a factory 60-2 tooth wheel that I have seen uses this setting) finally obviously the wheel turns at crank speed. That's all there is to it


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## o.g.johnson (Jun 1, 2010)

Lovely job, cheers Prof. I've written that down in my notebook. Finding that sort of concise information takes hours surfing websites, or one answer from a clued-up chap such as yourself :thumbup:


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## need_a_VR6 (May 19, 1999)

The only thing you'll have to watch with the hall crank is the input edge (I sound like a broken record!). If you're not picking up rpm or it's intermittent at first, check under diagnostics and do a tooth log. The missing tooth should be ONE big spike with 58 in between. If you have two big spikes, you need to invert the input. 

Ditto on the wheel settings, that's exactly what I use for MS2/3.


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## o.g.johnson (Jun 1, 2010)

Gotcha :thumbup: I think I'm with you there, cheers! I'll have a play with it over the weekend.


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