BigEz209

I have a 94 z28 a4 with mid lengths and no cat. Other then that it's stock. My problem I'm having is when I first start it up after it sits for awhile it idles really low at like 500. It should be idling at about 1,000 till it warms up. I give it some gas and rpms climb normal and let go of throttle it will drop lower then 500 and lights flicker like it wants to shut off. After I drive it, it runs fine and idles normally. Just only happens at cold start. I was told it could be my tps. Just want to get some other opinions to see what maybe it could be. Any help is appreciated. Thanks....