Lotus TURBO ESPRIT Service Manual page 384

Page 12
SECTION LD
LD.
5.
-
FUEL
INJECTORS
The fuel injectors are fitted into the inlet manifold, and continuously inject fuel
into the intake parts whilst the engine i s running.
The injectors have no metering function but open at a specified pressure and inject the
fuel allocated to them by the fuel distributor.
The injector nozzles are fitted with a valve needle which vibrates at high frequency
as the fuel flow pressure lifts the valve on and off i t s seat, producing a finely atomised
spray
Fuel atomisa tion i s further aided, especially at low engine speeds, by an air stream
flowing around the injector
This air stream i s supplied via a passageway running across
the top of the inlet manifold, and a hose connecting with the intake plenum.
When the engine inlet valves are closed, the air/fuel vapour cloud formed, i s stored i n
the intake port,
. .
to be drawn into the cylinder when the inlet valves open again.
When the engine is stopped, the fuel pressure drops below that required to open the
f
njector valves, so shutting the valves
and
preventing fuel dripping into the ports.