Lotus TURBO ESPRIT Service Manual page 352

Page 4
LB.l
.
-
GENERAL
DESCRIPTION
-
Two fuel tanks are fitted, one ahead of each rear wheelarch.
A
seperate filler
neck with lockable cap i s provided for each tank, and the two tanks are
interconnected by a large bore balance pipe.
A
single sender unit f o r the
fuel gauge i s fitted into the top of the right hand tank.
Fuel i s fed from the left hand tank to a high pressure turbine type fuel pump
capable of delivering
100
litres/hour.
Fuel i s then fed through a canister filter,
also fitted beneath the left hand front corner of the engine bay, and. then to the
f u e l pressure regulating valve mounted on the rear of the carburettor plenum
chamber.
A
spring and diaphragm system i n the regulating valve, i s adiusted to set fuel
pressure to
3.5
Ib/in
2
during idle and light load conditions, but as inlet
boost pressure is developed, a sersing pipe from the diffuser (via the rear carb.
cold start banjo) adds a boost pressure signal to the spring pressure to ersure that
2
fuel pressure is maintained at
3.5
Ib/in
above boost pressure.
Excess fuel supplied to the regulating valve is returned via a port i n the bottom
of the valve to the right hand tank, whilst two seperate pipes from the valve carry
fuel to the front and rear carburettors.
LB
.2.
-
CARBURETTOR THEORY
OF OPERATI ON
- . - - -
Carburettor Type
-
Dellorto DHlA
40H (2
off)
Fuel Supply
Fuel from the union
(1)
passes through the filter
(2)
and reaches the needle valve
seat
(1 8),
where the needle valve
(17),
attached to the float
(15),
controls the
fuel flow into the float chamber, thereby maintaining a constant level.
The float chamber i s vented to the plenum chamber through the hole
(4)
i n the
chamber
(3).