I'm not sure if the starting issue and the hissing are connected, but that would be my guess. Engine will turn over but die unless I press on the accelerator or go directly into gear & motion. When engine is running, I hear hissing sound like air escaping under the hood, and air sound is consistent between idling and accelerating. I'm pretty sure the issue is unmeasured air entering the system from a bad seal or hole in a hose somewhere, maybe most likely somewhere around where that duct tape (placed by prior owner) is in the attached photo, but is there anything else this could be?

 

The picture you have is showing the power steering pump and the duct tape is on the pressure hose. Not likely the cause of the hissing sound. Check for leaks in the large accordion tube that goes to the throttle body. Also check the throttle position switch to make sure it "clicks" when the accelerator goes to the idle position to enable the idle air controller.

Check out the following links:

https://www.brickboard.com/FAQ/700-9...PositionSwitch

https://www.brickboard.com/FAQ/700-9...irControlValve

https://www.brickboard.com/FAQ/700-9...itchAdjustment