I remember I had this problem and the issue is that you have to get to stage 5 A/B setting. My joystick throttle needed calibration for that. Alternatively I think you can use F4 to ensure 100% throttle setting.
Yes, but I have done that. Still no cigar.
Cees

Whatever.. she pulled down and the blast deflectors came up so I presumed all was good. Got a telling off for not being at zone 5 (I thought I was) so pushed the throttles to the stop.. waited for the needles to bend then hit shift+spacebar. I didn't actually leave like a scolded cat but I reckon 150kts was up as I left the deck. I've no idea where the inlet ramp controls are but I didn't sink to the sea so got away with it. 
Wish it was already weekend!

With V1.20 the AS Tomcat has a place on the podium in the "The Very Best Fighter Jets for FSX" category. 