Engines don't respond to throttle in some dls

Gentlemen,
Some of the models I've downloaded work perfectly except for one little problem - the engines do not respond to the throttle on my joystick or the F1-F4 keys. But I can see the throttle levers on the quadrants moving!
I am running FS2002.
Any ideas how to fix this problem?
Thanks.
Some of the models I've downloaded work perfectly except for one little problem - the engines do not respond to the throttle on my joystick or the F1-F4 keys. But I can see the throttle levers on the quadrants moving!
I am running FS2002.
Any ideas how to fix this problem?
Thanks.