[TR] TR4A - How is this possible?

[Randall]

> How is this possible?  How can any fuel/air make it into the intake manifold
> 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