What Does A Vacuum Leak Screw Up on a LT-5?

[Erik]

Just was mulling this over las night. Out of curiosity, what is effected by a vacuum leak on an LT-5? How would a vacuum leak effect operation or drivability?

[Young1]

One type of leak will give a high idle. Another type will give a code 61, limit rpm to 3,000, and lock out the secondaries. Another type will have the vacuum pump running too much. Another type will render the cruise inoperative. Another type will render climate control doors inoperative. Did I miss anything?

[Matt B]

If I remember correctly there is an article on Marc's page where he translates certain leaks into idle rpm increase. Very interesting read.

I'll see later if I can find it and if so I will post a link.

[jrd1990zr1]

Originally Posted by Young1

One type of leak will give a high idle. Another type will give a code 61, limit rpm to 3,000, and lock out the secondaries. Another type will have the vacuum pump running too much. Another type will render the cruise inoperative. Another type will render climate control doors inoperative. Did I miss anything?

Which vacuum leak causes the cruise control to go out?