Crazy Idling

When I put the clutch in, my rpm dips really low, like to 200 and then it comes back up and then it trembles usually higher than normal idle like at 1000.  It also surges sometimes while i'm just sitting at the light.  Any one had this problem or can suggest a possible solution?  It's torture driving my car like this haha

Oh yeah, it's a 91 240.  Thanks!

Hey, I have a '91 240 and it does ALMOST the same thing. RPMs bounce to about 300-400 at certain times (usually if I downshifted to second and almost stopped in second). RPMs are very unstable and constantly bounce from 500 to 700. I've seen them go as low as 250 at one point. As a response, I changed the plugs and wires. It idles a little better now, but it still does the same thing. This only started happening after I put some mods on it, so... do you have any mods on your car??? If you do, it's probably just the ECU adjusting itself to the newbies <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt=':)'>.

Irena

[Mennis]

Thanks, I'll check that. &nbsp;The only engine mod I've done is an intake but this problem has been an ongoing thing, but doesn't happen 100% of the time. &nbsp;In fact, yesterday my car was fine on the way to school but was messed on the way back. &nbsp;Some people suggested it could be the throttle positioning sensor/switch, is there a way to check that?

[ca18guy]

Check the ECU codes (goto 240sx.org FAQ for instructions) You can reset your computer by disconnecting your battery for half an hour.