UK Lee

On an AWD Turbo rallycar they will Cook an O2 sensor if the sensor is right off the Bellmouth. 

One Tuner I had for my Autronic said never put them at the bellmouth, even just for dyno running. .. SO there is probably some user preferences there!

You will be fine with the sensor in that location and it is better that the sensor is closest to vertical as possible to minimize condensation build up in the sensor on start up which can damage the heating element. 
There will not be much of a noticeable lag with the sensor that far from turbo.  Sensor on my down pipe is roughly the same distance from turbo. 
Closer to the turbo will reduce sensor life via extra heat. 

Should be:

Signal return       =  SENSOR Ground    Green        
Signal Line / TP  =  AN VOLT 3         Yellow / Black
VREF                   =  SENSOR +5v          Red / Blue

Cut the drain wire off at the sensor end.  You only ever want the shield grounded at one end and in our looms it is grounded at the ecu end. 
There is no "set in stone" rule as to which cavity is ground, a specific manufacturer will usually stick with a convention but not always.  Best to consult a factory wiring diagram.  The plug housings should have a 1 and 2 marking the cavities.  The polarity only really matters for the cam/crank sensors, all solenoids, temp sensors and injectors dont matter.  

The Link CAN lambda works fine without the termination.  At least it does if you are using our CAN interconnection cables.  Your OBD tool likely wont though.  

Hi Everyone , I'm very new to the world of engine management (being more used to contact breakers & condensers !) but am very enthusiastic ! .  I've been lurking for a while but this is my first ever post. I'm building a Cosworth YB Turbo powered Ford Escort Mk1 and have bought a new Link Monsoon G4x to take care of the engine management. I'm also using a boost control solenoid and a Wideband lambda controller. 
I'm going to be making my own wiring harness using a Link Loom A as the basis. I figured the best place to start would be to fill in the I/O table and use a schematic for myself to follow. i couldn't find anything that i could copy during a google search ( lots of mazda rotary stuff) but nothing for a typical 4 cyl turbo motor. I also looked in the PC Link help files , and whilst theres some great detail in there - its all split up into individual sections and i couldn't find a total 'system' wiring diagram . 
So , I've created my own - and here it is . However - this is my first ever go at doing something like this , and i'm bound to have made some schoolboy errors . Could i ask for the benefit of your experience , and ask you to take a careful look at my schematic and let me know if Ive got anything wrong please ?  
I've followed the wiring colours of the Loom A as best i can , and i'm sure that most of my component symbols are innacurate - but the important thing is are my ECU pins connected to the right places ? 
I'd really appreciate any guidance. 
Lee


Link Monsoon G4x ECU to Cosworth YB Wiring Schematic.pdf Link Monsoon G4x ECU to Cosworth YB wiring - header list.pdf

Yes, you can use that. There's really nothing electronic inside of it. Just a solenoid coil - which is ECU controlled by pulse width modulation.

I agree with @essb00: that's a basic PWM inductive (and therefore non-polar) solenoid and should work just fine.  Power to one pin, second pin to ECU ISC output (I usually use Aux Output 1 or 2).

Just first check the resistance of the solenoid.  99% of the ford ones are fine, but there is an odd UK one (from the CHV or CVH? engine) that is really low resistance and wont work.  The aux outputs can handle 2A max so it needs to be more than about 7ohms.
Also, be aware most of the ford ones are vacuum assisted, so they need to be oriented so that the manifold vacuum is on the correct port.  They dont work backwards.  You need to look at pictures of the original application engine to figure this out as some that even look similar are oriented visually reversed compared to others.  

Dont attach any ground will be the safest.  It will find its way though chassis and back to the ecu.
 
Yes, that is perfect.  
 
The flash/solid for two warnings can be done in the software, only connect lamp to one aux.  

You would set up your output to be a GP output triggered by a virtual aux for the CE light, or by oil pressure conditions.  
For Example:

I typically set up a GP rpm limit based on oil pressure vs. rpm if the sensor is available.  I use the same parameters to operate the light (i.e. active if GP RPM limit 1 is active, or below XX pressure).

You can with some conditions:
You might run into ground offset issues (slight voltage differences between the sensor ground and the ECU). You might need to make custom calibrations in the Link software for the sensors as they might not be one we have built in calibrations for. (Custom calibrations can also be used to counter consistent ground offsets but this isn't good practice). This can result in ground loops but not doing it can result in ground offsets, difficult question to answer.
My comment on this wasn't taking into account that the sensor was being shared, temperature sensors typically need a 5V pullup on the signal side as the sensor is just a resistor between the signal wire and ground, the AN Temp pins have built in pullup resistors where the An Volt channels do not.
This means that the Oil Temp sensor will be fine as the gauge will provide the pullup but if the water temp sensor has a pullup in both the gauge and the ECU it will not work properly.
Fuel pressure can be used for fuel corrections, oil pressure and temp are nice to have for logging and engine protection features. In my own vehicles I just have the ECU control an oil pressure light because I don't want to do pressure/rpm maths everytime I look at the gauge and a light immediately shows something is wrong.

3 wire pressure sensors you can usually share the signal - so for instance the one oil pressure sensor could be connected to both the gauge and the ecu.  You will potentially lose a little accuracy as the sensor is not referencing the ECU 5V or sensor ground but for oil pressure high accuracy is not usually critical.  It is useful to have both fuel and oil pressure in the ecu as you can use them for engine protection strategies as well as fuel pressure compensation in the tune.
For your oil temp sensor it could possibly be shared but you will have to do a bench test to confirm the pull up voltage that the gauge uses.  So power the Oil temp gauge up on the bench, (no sensor pluged in) measure the voltage accross the temp temp sensor wires.  If it is 5V you can share the signal with the ecu (direct to AN Volt, no pull-up needed), if it is 12V you cant use it. 
As for the question about why the pull-up is needed for the oil temp sensor:  There are two types of analog inputs - Temp inputs and Voltage inputs.  The temp inputs are designed to be connected to a resistance type sensor so they have a 5V 1kohm pull-up connected inside the ecu.  The volt inputs are designed to be connected to a sensor that is powered and outputs its own voltage so these inputs dont have a pull-up.  But your drawing didint originally show the oil temp sensor was also going to be connected to a gauge (which would have a pull-up built in) so if the oil temp is connected to both ecu and a gauge then the external pull-up in the ecu wiring would not be needed.
 

A couple of extra comments from me too.  Although yours is more drawn as a schematic than a wiring diagram, so your intent may be not be to wire as drawn - but if the coils a 3 wire only, then that single ground should be grounded to the cyl head - not back to the ecu.  
Also, the CAN lambda, since it is connected to a "noisy" power source, I would suggest adding the 22uf cap into its power supply/connector.  
For basic 4 cyl installs you can also get away with just a single power supply relay for everything, so you can do that if you want to simplify.  
I have attached a generic 4cyl drawing.
Monsoon-4-Cyl-Generic (2).pdf
As for the question about grounds, I would prefer both to the same point.  Can you show me this IO table that you downloaded - I cant see that comment in any of our current documentation.  
I think the "WCU" was meant to be "ECU".

yup
 
I read that one as ground to cylinder head but yes the coil grounds should go to the cylinder head not to the ECU ground wire.

Yeah I agree, not great wording on my part.  What I was trying to cover is if those particular coils only have a single ground pin or multiple.  Probably K20 coils with 3 wires if I were to hazard a guess. 
Some coils have more than a single ground wire - and when they do they are usually connected to circuits that are better to be kept as separate loops.   For instance the common IGN1a, they have 3 isolated grounds - secondary winding ground goes to cyl head, primary winding ground goes to batt neg, logic ground goes to ecu sensor ground.  They would usually work fine all connected to the same point, but will be more tolerant to noise and will be more resistant to false triggers if done separately.
In this case if they are 3 wire coils, I would typically run the ground wire from each coil separately to the ground point, but then all crimped into a single eyelet at the cyl head.

Ok, that looks like an old one.  Here is the current:  http://linkecu.com/documentation/MonsoonXQuickstartGuide.pdf

It is connected to the same power supply as coils and injectors and idle valve, these are all inductive devices so every time they turn off they send a high voltage spike back down the wire, sometimes as high as a couple of hundred volts.  The CAN lambdas are particularly sensitive to these inductive spikes.  
The CAN lambda quick start guide shows 2 alternative diagrams.  The first one uses its own relay connected directly to the battery (the battery will filter out a lot of these spikes).  The alternative diagram shows it powered from the ECU relay like you have here so it uses a 22uF capacitor added acroos the power wires (this filters the spikes).  Pic below.
Since you have an aftermarket tacho it will be fine connected direct to the ECU.  Escorts originally have a "High voltage" tacho that would not work connected direct to the ecu which is what Vaughan was informing.

For your oil temp sensor connected to AN V4, you will need to add an external pull-up resistor to 5V like below.

Your oil temp sensor will need a pullup to work on AnVolt 4 (typically 1kohm with one side to the An Volt 4 wire and the other to 5V).
Typically you want both of your WCU Power Grounds (Pins 25 and 34) to go to the same point which would preferably be the engine block ground.
Depending on your tacho type you might need a converter or to do some modification to make it work with the ECU signal (Tachos that are intended to be fed by a coil negative typically need some modification or some form of booster to work from the ECU's Low side PWM drive).
Other than that it all looks good.