high idle question

[young7303]

ok the car previously had a blown motor, so i installed another ka into it. my problem is that I can't get the idle down to a consistant 750. I've unplugged the tps and then set the idle screw so it idles at 750 but when I plug the tps back in the idle goes up to 1100 rpm. and when it's at 750 the engine shakes. am I missing something, (obviously)? also the power is not there it feels very weak and sluggish. any suggestions. need more info? thanks for the help.

oh it's a 90 240sx, ka24e engine

ok now I've got the idle so it stays at 750... but the car runs rich (fuel smell out the exhaust) and it's got a rough idle and low power. I've set the idle screw, tps, distributer, replaced the coolant sensor (on top of the upper coolant hose) and checked the o2 sensor... but the o2 wire (off the harness was looking a little green (oxidized in one spot) so I cut and respliced the wire. what else could cause this problem? thanks again.
Modified by young7303 at 5:22 PM 9/15/2005

[NISTECH]

possibly a leaking injector. Get a fuel gauge and do an injector leak down test.