Thermal Ignition Advance; Vacuum Circuits; Water Temp - Lotus TURBO ESPRIT Service Manual

SECT/ON EMC
EMC.2.
-
T H E R M A L
I G N I T I O N ADVANCE
The t h e r m a l i g n i t i o n advance system i s d e s i g n e d t o p r o v i d e
maximum i g n i t i o n advance a t low e n g i n e t e m p e r a t u r e t o a i d c o l d
d r i v e a b i l i t y and i n c r e a s e i d l e speed.
The d i s t r i b u t o r i s f i t t e d w i t h a double s i d e d vacuum advance
c a p s u l e , one s i d e of which
i s
permanently connected t o t h e plenum
chamber ( b o o s t p r e s s u r e ) . The o p p o s i t e s i d e of t h e c a p s u l e
i s c o n n e c t e d , v i a t h e Thermal I g n i t i o n Valve
( T . I . V . )
and I g n i t i o n
S o l e n o i d Valve (I.S.V.) t o e i t h e r t h e vacuum pump o r t h r o t t l e edge
d r i l l i n g .
The T.I.V. i s f i t t e d i n t o t h e c e n t r e of t h e i n l e t manifold
w a t e r r a i l , and a t c o o l a n t t e m p e r a t u r e s below 60°C, connects
p o r t s ID' and ' 1 ' . Above 60°C, p o r t s 'D' and ' 2 ' a r e connected.
The I.S.V. i s mounted on t o p of t h e r i g h t hand f u e l t a n k board
and i s c o n t r o l l e d by a t h e r m a l s w i t c h f i t t e d i n t o t h e t h e r m o s t a t
h o u s i n g o u t l e t p i p e a t t h e f r o n t of t h e e n g i n e bay.
A t
c o o l a n t
t e m p e r a t u r e s below 70°C (on r i s e ) t h e
I . S . V .
i s e n e r g i s e d and
c o n n e c t s p o r t s ' 2 ' and
' 3 ' .
Above 70°C t h e s o l e n o i d i s de-energised
and c o n n e c t s p o r t s
' 1 '
and
' 3 ' .
The I.S.V. i s de-energised d u r i n g e n g i n e c r a n k i n g r e g a r d l e s s
o f c o o l a n t t e m p e r a t u r e .
Vacuum C i r c u i t s
Water
Temp:
inlet manifold below 6 0 ' ~
A t
c o o l a n t t e m p e r a t u r e s
( i n l e t manifold) below 60
O C ,
t h e T.I.V. and ( e n e r g i s e d )
I.S.V. d i r e c t a vacuum
pump s i g n a l t o t h e d i s t r i b u t o r
advance c a p s u l e t o provide
o v e r 30°C i g n i t i o n advance
t o a i d c o l d d r i v e a b i l i t y and
i n c r e a s e i d l e speed.