90 Throttle Body butterflies- how tight should they close?

[Corvette95]

Checking for a vacuum leak before I pull the top end , I am using my custom made smoke machine, the only place I am seeing smoke from is out of the throttle body valves. I have the machine attached at the pump line +/- 5lbs of air pressure. Would this be normal leakage or are my butterflies worn?

[Ccmano]

Unless your having a high idle situation I wouldn’t go crazy with it. Just do the “minimum air” adjustment when you get it back together. Most people wipe the DAG throttle plate sealer away thinking it’s dirt anyway. Here’s the write up on that.
http://www.zr1.net/forum/showthread.php?t=27764&highlight=Minimum+air+adjustment

Here’s another good thread on the subject.
http://www.zr1.net/forum/showthread.php?t=27773&highlight=Throttle+body
H
:cheers: