I've got a strange question here.
when i let my car,let her warm up for a minute
or 2, depending on the temp, she drives fine, holds the idle nice, around 900 rpm's

but when i just let her run for about 10 to 20 sseconds and put her in drive, it feels as when i'm driving the car that she is surging but the rpm's are reading steady and when i come to a stop quick the will dive down to 500 rpm's and then go back up to 900 rpm's why is this?

thanks
toiny