Nissan Repair: Infiniti 1996 I30 stalls when Idle, fuel pressure regulator, air control valve

Question
My 1996 Infiniti I30 stalls in idle recently. When it's cold the RPM is between 750 to 1000 but when it's running hot the RPM dips to 600 or less in idle. When it hits 500 my engine stalls. Sometimes it stalls on Starting up the car too, repeatedly until I step on the gas. When I turn on the AC the RPM is around 700 RPM but as soon as I turn off the AC the likelyhood of a stall in idle is great.

I just got an oil change and got my IAC valve replaced and new hoses installed. Still stalls. What could be the next problems to check for on the list?  

Answer
David,

You are probably getting unmetered air.  Check for hoses that are not tight or ones that are cracked.  Also, check to make sure that the fuel pressure regulator is in good working order.  I assume they cleaned the throttle body when they changed the idle air control valve.  If this is dirty it will screw up the idle when it is warm.