I have a 2006 ford fusion and lately it works fine if I lightly press on the gas. If I press on the gas with full force though it will rev up the RPM's but there will be no power and my car won't speed up. There is no engine light on or any lights on when I look at the dash. It will only speed up if I'm lightly pressing on the gas.
Any ideas on what it could be?
(automatic Transmission)
If the engine is capable of breathing mixture and spinning at the higher RPM, it should be producing more power than at lower RPM. Means it's likely getting eaten up somewhere in the drive train before it gets to the wheels, and the most likely candidate for that would be the torque converter as @Zaid suggested.
Do you have a scanner for your car? Does the '06 Fusion have a sensor for transmission fluid temperature? If it does, see if it's above normal. If so, that is probably you're issue. You can also check the color and smell of the fluid. If it's dark red or black and smells burnt, that's bad.
Hope that helps!
