It has not.
However the Disco decided to misbehave yesterday. I think it has dropped a plug wire. So, I have to order up new wires /plugs and get them installed to make sure. The number 4, which is the one showing a misfire, seems a little brittle. So, I am thinking the core has cracked. I washed the engine off last week and remember moving the wires around when I was rinsing it. I initially thought it was just wet as I had not driven it since hosing the dust off of the engine, but after running it yesterday to get it warm and letting it sit overnight, it is still idling rough.
I will update as soon as I get the wires replaced and make sure that is all that is wrong. As the truck never gives a moments trouble normally, I am fairly confident it is just brittle wire cores.