and the throttle position sensor. The diagram on page 82 showing 14cux inputs and outputs shows the vehicle speed sensor as a input to ECU. How does this work with the system?

 

There is no crank position sensor on a dizzy motor.
The VSS sends the road speed signal to the ECU, which then sends the signal to the speedometer as well as helps with engine fueling.
MAF, VSS, O2's, engine temp, air intake temp, engine RPM, TPS...all tell the ECU how much fuel the engine needs, if any one of these is out of whack then the ECU may feed it more fuel then needed.
If the engine needs "X" amount of fuel but is being fed "Y" amount of fuel your exhaust emissions will be wrong.
There are other factors as well, worn out spark plugs, bad/cheap spark plug wires, bad dizzy and rotor, weak coil, those will all provide weaker than needed spark which will not burn the fuel completely, increasing emissions.
Using cheap fuel, increases emissions, clogged air filter, dirty throttle body, engine running to cold because of a bad thermostat, all increase emissions.

 

I have wired up a Rovergauge to read fault codes from my discovery and it works great! However as suspected I am getting a MAF fault code and no volts (airflow)through it. Something that also gets me thinking is that I don't have any Lambda readings. they just sit at zero (no plus or minus) is this because the MAF is faulty? the lambda sensors are not getting a fault code.
If I reset the codes that works fine and my "check engine" lamp comes on with ignition and goes out when the car is started. If I stop the car again then turn ignition on the check engine lamp flashes very quickly and goes out before the engine is started... any thoughts? before today the check engine light had never really been on at all.

 

If your lamba sensors are sitting at zero they are not working, the volts on them should be moving quickly from .01v to 1.0v.
They will work independently of the MAF.
Now, you need to check and make sure you actually have lamba sensors, not all DI's have them, some versions sold in ROW (rest of world) did not have them nor did they have catalytic converters.
If you do have them, and everything is reading as not working, it very well could be your computer is bad.
I think you are going to have to try another MAF to know for sure on that though.

 

I know the lambda sensors should be giving a reading like you say (yes I have 2 lambda sensors) Would one bad sensor mean I would get no reading? or do both need to be bad? One of the sensors is new and only driven 200km...

 

Each O2 sensor has a separate input to the ECU, on pins 23 and 24. You should be able to measure there or at the connector by the sensor, to frame ground, and see voltage changing.

 

Link is dead.

 

A bad sensor would either read 0.0v, 1.0v (totally dead)or change volts really slow.
If the heating element in the lamba sensor is bad you will get a code for that.
If both sensors are not showing up, and you just had one replaced...I'd say they came unplugged.

 

Ok finally got my a replacement MAF today in the post and guess what it works not like the other brand new one I bought of ebay!! All volts are reading correct, I can analyse all correct reading with my Rover gauge setup.
Lambdas and MAF working correctly and the whole point of the exercise was to get my CO levels down as they were around 11-12% !!! now it is at 0.22%... thats a hell of a difference. Just for information the first MAF which was a new unopened unit didn't work which I bought on ebay probably came from the china. The 2nd one (the one that works) is an original part 2nd hand from a salvage yard. It cost me double the money for the used original LOL! but I don't care it works!!!
Thanks for all the help
Jason... now with emission friendly Disco 1..

 

Thank you for reporting back!!
Glad to hear all is well once again.