97 sable idles low and rough

My sable is idling at 500-700 RPM(and rough), but sometimes it cuts out when I stat in the morning. Changed the Idle air control. also cleaned throttle body. problem stops if the car is jacked up slightly. any help would be appreciated. Thanks

When this is happening, what happens if you step on the accelerator?


It acts normal. once I give it a little gas it runs great. it is just when I first start up