I have a manual and when I rev it up the rpms seem to rise slightly and drop slowly, a few times it seem to take well over 7 or 8 seconds, I dont have a tach so Im not totally sure if the rpms go up, Im sure some lube would fix it but im not sure where
how many miles you got on it? i'd say take off the throttle body and clean it first and make sure, if you do, you take off your throttle positioning sensor then report back.
check for leaks in your vaccum lines too