Reverse Problem

[popogto]

Hi all!

First Post for me here

Ok! lets get straigt to the point.I have a 89 KA24e powered 240sx Fastback Automatic. STOCK!its got 150,XXX miles on it, runs smooth most of the time.

heres the problem, when i put it in reverse, and let go of the brakes, the idle rpm drops to about 400 to 600 and fluctuates.

im new to this car so i dont know if thats supposed to happen. any information is greatly appreciated!

[Arrow]

my 1990 manual transmission does something similar but then again it is manual, and I am not familiar with the AT's much... With mine the idle drops a little to about 600-800 (from almost 1000) and will fluctuate if I don't give it gas... But I believe that is simply b/c mine is a MT and that the gear ratio's for MT's reverse are higher than the AT's ratio...

Probably no help to you but hope that someone else can answer your questions!