Idle Issue

[Nissan24z]

Sometimes my rpm's will dive around 600-500 either when letting off gas to press in clutch or sitting at a light. Occasionally it will even stall. What's this valve you can clean they are talking about in the FAQ's area and where's it located? Could there be another issue or should I start there?

Oh yea it's a '95 240sx-se

Thanks!

[Hijacker]

the valve would be the AIV unit located on the intake manifold. It has the screw you turn that raises and lowers the idle speed