Ok, found the time to look at it this morning.

I have a craftsman meter, I put the black lead that is in the port labeled COM into pin 3 and with the ignition on and the diagnosic LED ON as per the instructions I get a steady 85.1% reading.

I started the car, it ran a little rough at first, but started fine with a little gas applied. I warmed it up whilst seeing the following.... The meter reads with the engine running at idle also about 85%.
When I rev it, it goes down to 45/50% and if I hold the revs steady it comes back up slowly to 85%.

Here is where the fun starts.

It is warming up nicely... I shut it off to read the Landis instructions.... and now it wont restart!
I have a good healthy spark, before anyone asks!
Its still warm at the moment, so it wont start... it does not even fire at all... just spins.

HELP!!!!

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2009 Mercedes ML320 Bluetec