Buick Park Evenue 91, wont accelerate. In reverse it accelerates just fine, maybe not exactly the same as before but still ok, but in forward it seams that it is in higher gear than it should be. It eventualy comes to 100 mph but even than it has no good acceleration. Only in reverse it accelerate ok. Also the sound from engine and exhaust is not any more so strong and powerfull like it used to be before. Problem is I live in Croatia (Europe) and here is no good mechanics for Buick car, so I'm prety much on my own and help from internet. I can order part from US but first I have to diagnose the problem. So far I only fill up transmision fluid because it is leaking and it was way below it should be, but nothing changes. Thanks, Simon.