I am chasing this problem down. The car drifts at idle and if I push the accelerator to the floor there is a hesitation and the car never really gets going. Doesn't reach redline. If I let off a bit and it gets into the next gear it pulls hard and quick.

What I have done so far.

New Voltage protection relay
New fuel pump relay
replaced injectors and seals
Cleaned Idle control valve

The car is running much better than when I bought it just not quite there.
I am guessing I have a small vacuum leak somewhere causing the idle to drift but not sure. Building a smoke machine to check for leaks.

May also be low fuel pressure I guess, need to check that. Possibly pressure regulator?

Help me out here guys