Subject: [TR] TR4A - How is this possible?

From: "G.D. Huggins" <[email-masked]>
Date: Tue, 5 Nov 2013 20:37:16 -0600

All,

Got myself a brand new vacuum gauge, so I am doing some tuning tinkering this
week.
I have managed to get the car idling with the SU HS6 throttles being
completely closed.
How is this possible?  How can any fuel/air make it into the intake manifold
with fully closed throttles?

Stay Frosty,

Guy D Huggins

** [email-masked] **

Archive: http://www.team.net/archive

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From: Randall <[email-masked]>
Date: Wed, 6 Nov 2013 3:15:27 +0000

> with fully closed throttles?

The throttle plates never seal perfectly.  Perhaps yours are worn (or misaligned, etc) enough that they pass enough air to idle.  

Or, maybe you have air coming in some other way (like through the PCV valve), and the mixture is rich enough that the leakage past the plates plus the external air is still a combustible mixture.  Leaking float valve, maybe?

Randall