We are in time for a buy and neeeed advice

[Madmax]

I´m new here at Beretta.net from sweden.
I Posted a Post but no answers. so I trie agian becuse I must leave the seller a decision.
At a testdrive nearly everything worked but when standing still, parked. I slowly increase the rpm and when I doing that, the motor seems not to work on all cylinders, it do not go smooth.
But if I just kick the accelerator, motor responds quckly and smooth.
when driving it fells no problem....
Pleas is there anyone out there who has any clue?
note. the batteri was bad, can that make same bad data in the computerbox?

[rweatherford]

The throttle position sensor could have a bad spot in it, which could cause problems that you would notice at slow throttle application.  Usually they wear out in a common range that the pedal moves first.

Some engines have a certain RPM that they have a harmonic imbalance and there will always be a vibration at that RPM.  

Usually the engine control module will learn the idle and fuel parameters within a few driving cycles.  Sometimes the idle on the older V-6's needs to be run through and idle procedure to help it learn properly.

Even a bad motor mount can make the engine feel too rough.