I’m thinking it’s my Iacv but I’m not entirely sure
Car starts and drives normal. After 20 minutes I’ll shut the car off. When I restart I’ll get a a humming noise around the intake manifold. The idle will be lumpy. To me it’s sounds like it’s from the Iacv. After a minute or so the humming will dissolve and the idle will settle. But sometimes the humming will be faint and it sounds like it’s coming from the fuel rail. Any suggestions that I might be overlooking would be appreciated

 

prolly your Iacv

 

Ok so I now figured out it’s not the Iacv. Instead it’s coming from the fuel rail. Either the fuel pressure regulator or the damper. When I remove the vacuum tube from the regulator. The noise goes away. Does this sound like it’s the fuel pressure regulator issue? Damper is new. Also does the sealing washer with the tabs for the damper have any affect? I’m using a generic copper sealing washer