got one for the experts

[reags8]

My IAC was sucking air through the black cap and ******. I replaced the IAC with a new ford motorsports IAC exact same part number, identical right down to the black cap and ****** after installed the new one would suck air at idle as well.
I thought any air introduced after the MAF was considered a vacuum leak ?

Anyone, anyone . . . . Bueller, Bueller . . . .

Reags

 

[NinjaMike]

Any incoming air after the MAF is unmetered and is a vacuum leak. For curiosity's sake, why don't you try to cover the cap up and see if you still can feel a leak.

Did you replace the gasket?

 

[reags8]

I can pull the cap off - Should I try and plug it ?
Yes I replaced all the upper intake gaskets except for the runners.
Reags