Help? idles bad

[Fred9981]

my car when you turn it on if idles funny it reves up to 2500 rpms and then goes down to 1200 rpms and the rpms go up and down 100 to 200 rpms i tried to set the idle speed by adjusting the the screw throttle body but nomater where i set it it wants to turn off and it goes back up

it only idles high on park when i have it in gear its fine 800 rpm

95 gsx

please help me

 

[TheTSiGuy]

Search for idle surge.

Its a start.

 

[Woody91GSX]

Check for a BISS O-Ring. If it's there, maybe get a BISS screw.