A vacuum reading of 17 at idle is on the low side to begin with. A normal reading is up around 20. So you likely have either a vacuum leak or the bad valve is slightly open even at idle. If you have the time, it wouldn't hurt to do a compression test while you're driveway bound, just to rule out some possibilities.

 

Hi, Dansendlessprojects -- Had been a very interesting and educational thread.

A pity, it is not continued until a happy ending,,,

Can you not update when you may find time???

Thanx in advance.

Jorghenry - Japan