engine rpm, how responsive,, need tuning advice Options

[freezing14]

the car is a 72 1.7 ( bored to 1.8) d-jet

OK I finally got the engine in the car after the comlte restoration of the body,, ( when i got the car the engine was in a box) i got the whole thing to start upo just fine , it finally run without backfire ( the valve were tight) now it run good no oil leak, ( i still have not put the gas tank in and the drive axels) when i give gas right at the TB the response is fast but it seems like it takes time to go back down,, i know most of the car are different but my audi ( 2000 S4) rev down as fast as it goes up, my previous one a 96 A4 was quite a bit slower to go up and down anyone got a sound file of the rev and back to idle?? , what would cause the rev to stay up and go down slowly??

thanks