Photo Detector circuit question?

I am using part number: OPB607A. It is an object sensor. I was wondering the circuit to get it working. I have a 1K from emitter to ground and a 160 ohm on the diode to limit current. It acts like it is always detecting. I get a voltage around 3.8V across the emitter to ground. Am I hooking this up right?

You only tell half of your pin connections. I would normally use:

1 +5V
2 1K to ground
3 +5V
4 160 to ground

NOTE that pins 1 and 3 are on opposite corners of the device!

Try disconnecting the LED and see if the voltage stays the same. Be sure that the detector is shaded from ambient.