Crank position sensor polarity
Turbo Mini Forums

This may be a silly question, but i couldn't find an answer on the autosports site or here. Basically i need to know how to tell the polarity of the crank position sensor. Its from a fiesta and it has 2 pins, but with no indication as to which is + and -

Anyone know?

Cheers
Dan.

My build thread: http://www.turbominis.co.uk/forums/index.php?p=vt&tid=454802

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I don't know how to measure it.
But if you don't get a spark switch the wires and try again.
You wont blow it up if you connect them the wrong way. It just won't work.

there is nothing wrong with a A-series that a turbo can't fix.

www.turbomini.nl

Thats what i was going to do, but it would be nice to try and do it just the once.

My build thread: http://www.turbominis.co.uk/forums/index.php?p=vt&tid=454802

Flickr: http://www.flickr.com/photos/85313398@N02/

Rod S explained which way round the go, but it was some time ago. Have a search.

I've tried searching Andy to no avail! Can't think of any other words to search

My build thread: http://www.turbominis.co.uk/forums/index.php?p=vt&tid=454802

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it will work both ways but one way is unstable and the timing jitters about the other is correct,

this is a good thread

http://www.autosportlabs.org/viewtopic.php...f66b1db7ed35b79

Edited by Brett on 8th Oct, 2012.

Yes i moved to the darkside

Instagram @jdm_brett

I can't find it now...

Ah that is what i was after brett, cheers! And i'm glad i'm not going mad Andy.

My build thread: http://www.turbominis.co.uk/forums/index.php?p=vt&tid=454802

Flickr: http://www.flickr.com/photos/85313398@N02/

It will only work correctly when wired correctly, yes they are polarity sensitive.

But what actually happens when it is wrong will largely depend on what ecu is connected to it and how it decyphers the signal.

basically the sensor will still read the wheel and create a voltage, but when the wiring is reversed the signal trace on a scope is reversed.

So if your ecu is looking for a falling edge trigger...it simply wont see it ( you hope )
Or if it's looking for a rising edge, again wired wrong it may not see it.

the problems arise when the ecu sees something and thinks it is a viable signal, which can lead to wrong or random ignition timing, which is bad.

The Motec webinars explain a lot

http://www.youtube.com/watch?v=mv0-9_JS8oA...channel&list=UL

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

Pardon my ignorance but I dint understand this falling/rising edge business.

Do I take it that we should be setting the 90 degrees away from TDC on the leading edge of the gap, rather than the middle of the gap?.

Halfway down this page:

http://www.locostbuilders.co.uk/viewthread.php?tid=112060

Geoff

This thread, second post

http://www.turbominis.co.uk/forums/index.php?p=vt&tid=329345

Schrödinger's cat - so which one am I ???

Edited by stevieturbo on 9th Oct, 2012.

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will