Idle problem, can anyone help?

1. Is it unusual for the idle to jump to 1,000 when I turn the AC on?

2. Sometimes after I start my car up the idle will be unsteady. It goes from 800 back down to 500, and it will do this for about 10 minutes until it settles down at 700. Does anyone know why this is?

BTW I have a 1996 240sx with intake and exhaust. thanks

the unsteady idle is probably a malfunction of the idle air control valve (iav). it's trying to warm up the car... usually, it will just raise for a few minutes, then settle down, but i've seen them jump around like this... you could replace the aiv, or run something like seafoam engine cleaner through the engine.. it may fix it..

cool, i've got the same problem on my '90
i'll try that

hey it may be your MAS that is messing up. Check that and see if it quits