Changed out my TB yesterday and found this.

You may want to check your vacuum line from your intake.
Mine had a small hole in it. Never even threw a code.
The line must have been a bit to long and at high speeds it touched the upper pulley which made the hole. Just a heads up guys.
I think I will see if I can get a better vacuum line to replace it.

Steve

 

I can go one better. My vacuum hose was cut clean it two by the pulley. No code, but the loud whistling was a dead give away.

I replaced it with more rigid 3/8" fuel line. Problem solved.

 

Are you talking about the line from the JLT and the rocker cover?

 

Yes, the hose that goes from the bottom of the JLT tube to the top of the passenger side cam cover. I saw the potential for pulley abrasion, and have mine ziptied to a bracket right under the throttle body. Can't see the ziptie, and the hose can't dangle on the pulley and get chopped.

 

I did the same thing. Worked like a charm.

Steve

 

I will check mine when son returns GT Thanks

 

It may be a bit overboard but I replaced mine with actuall steel braided 3/8" hose and fitting ends that I "had laying around"

-Dan

 

I imagine that would look much better.
Got pics?

 

I noticed mine hung low when installed. So I looped it over a wire (one which I can't remember off the top of my head). So it sits higher off of everything.

 

I found a hole in mine also after my mechanic re & re'd the JLT to do my headers and wasn't quite so careful about where that hose hung. It's still got electrical tape wrapped around it until I get around to replacing it...