Engine stalls and won't hold Idle

[jcquick]

I have a 93 240SX KA24DE w/ 90K miles on it. It starts up just fine and runs great, except it won't hold a steady idle. The rpm's jump up and down and then eventually it turns off. It accelerates just fine but it bogs up sometimes when I let off the throttle. Someone told me it might be vacuum sensor. Please respond. Thank you for your guys help.

[1991S13]

Check the ECU for codes...

Could be o2 sensor, plugs/wires, timing, distributor cap and/or rotor, or injectors.

Mine jumped around at idle and someone said maybe its a clogged injector, so I ran some STP injector cleaner through and sure enough it fixed it.

[xero1]

the O2 sensor only works when the car is at normal temp, and if you had a bad O2 sensor your car will run rich, i think your problem is a bad idle control sensor, turn the idle up and see what happens, does your idle go up when you turn the ac on? a big vacume leak would cause the car to cut off when its idling, look for vacume leaks