Home page
SPONSOR AD

Support our Vendors!  |  Advertise Here

Topic: Vacuum Leak!

in Forum: C3 Fuel, Emission Control, and Exhaust Systems


Already a Member?
Login
Not yet a Member?
Register for Free!

Vacuum Leak! (1/1)
 9/29/12 11:01pm
daveo76
Former Member

Send Private Message

Vancouver, WA - USA

Vette(s):
1976 Silver/Firethorn. L48, 4spd. Original 2 bolt, vortec heads, 9.4:1 CR, Speed Pro Cam: 224/224@0.050, 112 LSA, Eagle Steel Crank.


Joined: 8/25/2005
Posts: 857

Oops! I've been driving around with a small vacuum leak since I put the motor in and didn't even know it.  For those familiar with Q-jets: I left out the little hose that goes from the carb to the choke pull-off diaphragm.  Noticed that missing last night and put it on.  It runs better than it did before, but it's surprising how well it ran without it.  The biggest improvement is how it runs right after a cold start.  Without the pull-off working it was probably loading up and it surged and ran crappy for about 30 seconds after start-up.  Now it runs good right from the git-go.  I was also able to lean the mixture a little bit and let it idle a little lower, maybe I'll save a little gas now.  Idle quality has slightly improved and I think it took care of a slight miss I was noticing.  The choke-pull off's other function is to prevent the secondary air valve from opening when the choke is on, but I haven't been getting on it much (especially when it's cold) with the engine break-in so I didn't notice that too much.  

______________

 

1976 Silver/Firethorn.  L48, 4spd.  Original 2 bolt, vortec heads, 9.4:1 CR, Speed Pro Cam: 224/224@0.050, 112 LSA, Eagle Steel Crank.
Our Sponsors help support C3VR