"Wisp" sound at throttle body when accelerating / delayed response/ occasional dying

[EB4X]

Hey gang,
So lingering gremlin....installed new IAC / fuel regulator / camshaft synchronizer assembly -- CIL code was on for this -with this repair new upper plenum and fuel rail gaskets / new fuel injection o-rings where installed / also tried new throttle position sensor but coincidentally made vehicle run worse then used oem - chinese part.
So with hood popped open and manually giving engine some throttle by hand (for close observation) there is a DELAY at beginning of throttle acceleration accompanied with a wisp / hiss sound for a second. Anything in particular come to mind? Bad rubber throttle body gasket? Idles good for the most part but occasionally will go into a temporary rev up and down during first start up of the day-- in a mild way and then goes away -- and rare at this....which makes it a stumper. And with this situation occasionally will die if doing quick acceleration from stop.
'95 has old school OBD1 so don't have all the elaborate testing options.

 

[rasouth]

It sounds like maybe a vacuum leak. Extra air would make it hesitate and rough idle. The trick I use for finding a leak is to use starting fluid and spray around the plenum, air intake, EGR, etc. while the engine is running and listen for any change in idle speed.

 

[EB4X]

I had done that already......thanks for input.

 

[1991 sploder]

There's a screw on the throttle body, idle is supposed to be controlled by the computer. Back off the screw until idle is lowered but not further needs a fine adjustment just enough for the idle air control to take over sounds like runaway idle to me when the throttle body is letting In too much air.

 

[1991 sploder]

Also are you running stock intake with complete tube on it?

 

[C420sailor]

TPS was my first thought. You put a new OEM in there though? No TPS codes?