90 Throttle Body butterflies- how tight should they close? - ZR-1 Net Registry Forums

Corvette95 · 03-14-2020

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 · 03-14-2020

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....air+adjustment

Here’s another good thread on the subject.
http://www.zr1.net/forum/showthread....=Throttle+body
H

03-14-2020	#1
Corvette95 Join Date: Jan 2006 Location: Decatur, AL Posts: 1,119	90 Throttle Body butterflies- how tight should they close? 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? __________________ Corvette95 Registry and Forum (*************) 1989 C4 Conv Wht/Gry Auto Hardtop Top Flight SOLD 1995 C4 Coupe Purple/Blk 6 Speed 1989 C4 Conv Wht/Red Auto SOLD 1996 C4 Conv Black/Tan Auto SOLD 1994 C4 Coupe Wht/Blk SOLD 1995 C4 ZR-1 White/Gry #278 Dual Dunn Head SOLD 1986 C4 Coupe Black/Red 4+3 SOLD 1990 C4 ZR-1 Red/Red #0454

03-14-2020	#2
Ccmano Join Date: Jun 2006 Location: Sparks, NV Posts: 2,852	Re: 90 Throttle Body butterflies- how tight should they close? 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....air+adjustment Here’s another good thread on the subject. http://www.zr1.net/forum/showthread....=Throttle+body H __________________ 90'ZR-1 #1461 Red/Black Ported Intake, Degreed Cams, OBX Headers & Exhaust, Fidanza FW, Secondary Delete, Custom tune, C6 GS Wheels. Sold 08 C6 Z51 Crystal Red Metallic Sold Vararam Intake, Tune, Sold 05 C6 Z51 Red/Black Sold 90'ZR-1 #1723 Black/Gray Sold but not forgotten 91' Z51 L98 White Vert. My First, you always remember your first. Sold.