I recently looked under the hood thinking about what to do as in engine detailing and painting. For the up and coming Pontiac day next year at Englishtown,NJ.
I glanced over at the fuel pressure regulator(because it is shinney) and bam.
I had a perforrated vacuum line to the pressure regulator. Didn't hear a peep from the engine in regards to a vacuum leak, car ran and started fine, the idle was a slight bit lumpy but just alittle with 116k plus thought it was normal.
I look around my tool box and found some vacuum hoses, I had to slip the skinny one into the fatter one because the ends of fittings are different sizes.
Buttoned it up and took her for a spin, noticed a big difference right away in response even squealled the left front tire a bit.
So when checking your vacuum just don't look at them, apply pressure to them bend them check for cracks and perforrations.
My tip for the day.