Weird Vacuum Pattern

[ashaw3]

Redtop SR.

So before it would run -24 inHg -> 7psi -> -24 inHg just fine. But the car would die after letting off from 20 seconds or more heavy throttle.

So I cleaned the IACV.

Now when it goes -18 inHg -> 7 psi -> -24inHg -> -18inHg

I have heard -17 to -21 inHg is what its supposed to vacuum at. So what gives?

Yeah, its probably a vac leak somewhere, but i've tried and havent been able to source it.

Thanks in advance.