> >There is one part on this car that remains a mystery to me. What is
> >purpose/function of the Thermostatic Vacuum Switch? This switch is
> >the EGR system and is located on the lower radiator hose. It has
> >vacuum lines running to/from it to the carb, EGR valve and the 3 vapor
> >separators.
>
> >Barry H. Adams
> >74 Spitfire
Barry,
If the Spit is setup like a TR-6, the sole purpose of the TVS (in a TR-6) is to
reduce the amount of vacuum going to the vacuum retard diaphram on the
distributor, thereby advancing the timing and causing the engine speed to
increase at idle when the water temp goes above something like 180F. I don't
know if it's purpose is emissions related, or to simply move more air thru the
radiator to help prevent overheating at idle in warm conditions. There is no
connection to the EGR valve from the TVS on a -6, but could possibly be correct
for your Spit. Normally a EGR vavle does not operate at idle or at
full-throttle.
Hope this helps.
Steve Sutton
74 1/2 TR-6 - daily driver!
ssutton@ridgecrest.ca.us
35* 35' 39" N 117* 39' 44" W
|