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2 Wire / 3 Wire Crank Sensor
daveb666 - 20/8/13 at 10:24 AM

My zetec has a 2 wire crank sensor. The SBD loom I have purchased has a socket/wiring for a 3-wire crank sensor installed.

Should/Can I:

1 - Chop off the 3 pin plug on the SBD loom, fit a 2pin plug (if so which wires?) and use existing sensor
2 - Replace my 2 pin crank sensor with a 3 pin?

Ben_Copeland - 20/8/13 at 11:42 AM

You might find the Ecu needs a 3 wire crank signal. I'm pretty sure megasquirt does.

What's the recommended crank sensor for yours?

daveb666 - 20/8/13 at 11:49 AM

God knows ?! How do I find out?

XE ones are 3 wire.

big_wasa - 20/8/13 at 12:00 PM

First things first. What engine was the ecu configured for ?

I've not seen a duratec or newer but older Ford's are a two pin Vr sensor. A lot of Vag engines use a three pin sensor. Some are a vr sensor with an extra shield and some use a Hall affect sensor. These are power earth and sense.

If yours is configured for a vr sensor then you can just use the two you need. If it's configured for Hall affect then you will need to see if it can be changed.

Some ecu's use a seperate wire and you will just need to rewire, some use jumpers in the ecu and others will be done by software.

You won't get a three pin sensor to fit the block and read the fly wheel. You could use a Hall affect sensor on a trigger wheel but if the ecu had been configured for any thing elts other than a Ford it won't be set up for a 36-1 trigger patten.

daveb666 - 20/8/13 at 12:06 PM

ECU was originally from a Ford CVH running bike TBs.
MBE does allow you to change the relevant trigger wheel settings within the system itself, as I remember that from my vauxhall days.

big_wasa - 20/8/13 at 12:07 PM

quote:
Originally posted by Ben_Copeland
What's the recommended crank sensor for yours?


Its a zetec, so that's a two pin vr sensor. If used with something like megasquirt then you would have an extra shield that runs the full length from ecu to sensor but is just terminated at the ecu to earth to stop interference.

If the ecu was for an xe ? you will still need to change the trigger pattern.

big_wasa - 20/8/13 at 12:10 PM

quote:
Originally posted by daveb666
ECU was originally from a Ford CVH running bike TBs.
MBE does allow you to change the relevant trigger wheel settings within the system itself, as I remember that from my vauxhall days.


If it was an early cvh then it could be set up for a hall affect sensor in a distributor or latter ones had a vr sensor on a trigger wheel on the front pulley.

daveb666 - 20/8/13 at 12:34 PM

so my first attempt is going to be to reconnect the 2 sensor wires, ignore the earth and try it with my own sensor?

big_wasa - 20/8/13 at 01:28 PM

Is one of the three wires yellow ?

daveb666 - 20/8/13 at 01:43 PM

Haven't peeled back the shroud on the loom, I'll take a look tonight

big_wasa - 20/8/13 at 03:30 PM

I really want just hack bits and try. See what it was set up for and go from there. If it cant be changed to vr it will still be saleable as it is.

daveb666 - 20/8/13 at 03:34 PM

Too late for that as I replaced all the injector plugs this weekend!

big-vee-twin - 20/8/13 at 05:43 PM

The Duratec crank sensor is two wires, megasquirt uses two wires

Hector.Brocklebank - 20/8/13 at 08:45 PM

if its an MBE ecu then it should have details & "notes" on the sticker on the ECU

for example

Model of ECU

9A4B

Firmware

BOM Code: 1.8

Serial number

000*****

Then in the Notes section on the sticker you should have

Supplier = SBD

Ignition config = HSD

(in this case for using external ignitors, this is a hardware configuration and not user adjustable in the software)

Crank Sensor =H/E Crank

(in this case a Hall effect crank sensor

to clarify

2 wire sensors are usually classed as dumb variable reluctor sensors (hence VR sensor)

But they can have three wires on their plug the "third" actually being used in a shielding capacity and not connected to anything at the sensor end.

3 wire sensors are usually classed Hall effect digital sensors

with the wiring usually being

5v analog
0v signal
analog ground

Its might not be the best idea to just hack a plug off willy nilly, call to Steve @ SBD tomorrow & it will yield you the definitive answer as to wheather you can use a VR or H/E sensor in conjunction with your setup

But look Here & Here

And navigate to the wiring section for more info, anything else is just wild speculation and usually results in tears

[Edited on 20/8/2013 by Hector.Brocklebank]