Firs of all i am not crazy ( at least not clinically)

when driving my 84 384 electric qjet 5speed camaro

I step on the clutch and the idle is 1500 rpm on the nose. Blipping the throttle doesnt do any thing.

if i load the engine by sliping the clutch with out adding any throttle the engine rpm will sag as load is increased until a point where it will drop sharply to 900 i step all the way down on the clutch and it idles fine at 900-1000 rpm. if i blip the throttle again it will jump to 1500 ( exactly) i load it down and it will drop and idle fine.

it seems as if something is switching as the load decraeses rpm. maybe the timing is changing? i don't know i have trouble simulating the problem once i pull the air cleaner off and the engine cools with the open hood. It was suggested that maybe the MAP sensor is failing.

any idea's???