Here are the symptoms :
When you move your car from static, in the first gear, it stalls and the RPM drops. (the RPM is dead stable at 900 otherwise)
In any gear, including the first and second, the car seems powerless untill it reaches 2500 RPM, it feels like it is suffocated. It accelerates, but very slowly, though the engine produces a lot of sound. As soon as it crosses 2500 RPM, it gets a kick and the acceleration becomes perfect, as if it is no more struggling for air.
The fuel economy has dropped immensely. It used to give 19-20km per liter on highways which is down to 8-10 km per liter.
Here's what has already been done :
-Tunned (over a dozen times)
-Replaced clutch pressure plate
-Replaced Fuel pump
-Replaced Fuel Filter