When my car is warming up and the Tach is at 1500 RPMS, the idle fluctuates. After the car is warm and the idle drops, its fine. But if i give it a little gas and hold it at 1500 RPMS, it will fluctuate. So this rules out the thought of a vacum leak. Even while driving it'll jerk if the RPMS is at 1500. Somebody please help.

 

My Si did that after i installed my new flywheel. I took off my IACV and cleaned it out and lowered the idle down. Reset your ECU by taking out the backup fuse for 10 mins. See if your car is throwing CEL code 14???

 

TT.....

 

what are your mods? When did you first notice this. We'll need some more information about this. It could be plugs, wires, carbon on the throttle body.

Let us know

 

2001 b18c5, skunk2 intake manifold, 2001 p73 ECU/imobilizer removed, aem intake...

 

ttt

 

yea clean out the idle air control valve if that doesn help check out your PCV valve too..

 

Mine is doing pretty much the same thing I changed the TPS sensor, played with the idle screw adjusted the throttle cable and still no luck I am gonna try replacing my intake manifold.

 

Try a throttle body gasket. My ladies 98 GSR with a 95 throttle body was idling like this and we changed the throttle body gasket from an OBD2 to a OBD1 Gasket and its idling fine now.