Lotus TURBO ESPRIT Service Manual page 248

SECTION EMD
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Page
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7
Intake Hose/
Sidewall
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Interface
El - -
Engine Bay W a l l
ATC
Divertor
Grommet Securi ng
R i
ng
The'ATC f l a p v a l v e u n i t c o n s i s t s o f a vacuum d i a p h r a g m o p e r a t e d
f l a p mounted on t h e i n l e t o f t h e c a r b u r e t t o r a i r b o x , c o n t r o l l i n g
t h e a i r s u p p l y t h e r e t o .
A t
m o d e r a t e a m b i e n t t e m p e r a t u r e s t h e
a i r b o x i s s u p p l i e d w i t h c o o l a i r from t h e r e a r l u g g a g e compartment
v i a . t h e i n t a k e s i l e n c e r . I n c o l d a m b i e n t c o n d i t i o n s , when
a i r t e m p e r a t u r e i n s i d e t h e c a r b u r e t t o r a i r b o x
i s
below
2 0 ° C ,
t h e ATC f l a p v a l v e i s moved t o a d m i t a p r o p o r t i o n o f warm a i , r
drawn from a s h r o u d a r o u n d t h e e x h a u s t downpipe. The c o l d e r
t h e a i r b o x t e m p e r a t u r e , t h e g r e a t e r t h e p r o p o r t i o n o f warm
air
d i r e c t e d t o t h e a i r b o x .
The A T C s e n s o r mounted by a r u b b e r grommet i n t o t h e b o t t o m o f t h e
a i r b o x i s a t h e r m o s t a t i c a l l y c o n t r o l l e d vacuum p r o p o r t i o n v a l v e
c o n n e c t e d between t h e c a r b u r e t t o r p o r t s downstream o f t h e
t h r o t t l e p l a t e s , a n d t h e ATC f l a p v a l v e .
A t
a i r b o x t e m p e r a t u r e s
a b o v e 2 0 ° C t h e v a l v e i s s h u t , b u t a t l o w e r t e m p e r a t u r e s a
p r o p o r t i o n of t h e i n l e t m a n i f o l d d e p r e s s i o n i s d i r e c t e d t o t h e
ATC f l a p v a l v e t o open t h e warm a i r s u p p l y . The s e n s o r c o n n e c t i o n
w i t h t h e l a r g e r h o l e must b e c o n n e c t e d t o t h e f l a p v a l v e .
Connect to carb. ports
Connect to flap valve