Problems with engine 2006 4.4 Start the car, and turns off. I turn it on, and have to keep the throttle up with the gas pedal, there came lots of smoke, maybe bluish. This has been for the couple of days when it stands over the night. Then after I drive it all is good and no smoke and no blue or dark ( I am though not sure how the color is after cold start)
Engine is driven 100k miles. Could it be the maf?
Also when I rev the engine and let it drop the rpm falls to 500 like it almost turns off and then gets stable again.

You can run the engine with the MAF disconnected, try that see if it makes a difference

Sounds like a fuel issue. I had it before I changed my fuel pump and the injectors/fuel line/inlet manifold were cleaned.

I suggest to start with the cheaper stuff, chuck injector cleaner in and make sure you use good quality petrol. Then proceed with cleaning the inlet manifold, next the injectors etc. Also suggest to change the fuel filter. MY 2010 5.0 SC Galway green and sand interior!!
Have the Faultmate MSV2 Extreme to be tinkering with the settings etc. !!

Do the headgaskets go often on the jag engines?

sounds like a blocked crankcase vent.

Good point, could very well be something like this. I remember the BMW engine has some issues in that field with the PVC valve etc. MY 2010 5.0 SC Galway green and sand interior!!
Have the Faultmate MSV2 Extreme to be tinkering with the settings etc. !!

Stroker's probably got something there.