Hi K,
It may be that you need to enrichen the mixture for starting.
I take it they are not standard Val's?
Does the 2D/VC view include engine management controls? If so, there should be a mixture lever, you prob only have to lift it off the cut-off stop setting, and then try and start the old girls.
If the starter is spinning, and you do that straight away in QC/FF, then it's most likely fuel related, and if it's been okay before, and you've not changed anything then.....
Another quick test is to change airfiles (rename etc) with say a standard Dauntless et al, and see if that cures it, that will indicate more likely it's an engine setting that needs to be used.
Why there is a difference between QC/FF and a mission, I'm not sure, it may be start location height, and the need/no need for a richer mixture?? Or possibly the mission sets easier flying/engine management skills?
Cheers
Shessi