Lotus TURBO ESPRIT Service Manual page 425

SECTION LO
Page
53
LD
27
-
WIRING
DIAGRAM
SCHEMATICS
-
FUEL INJECTION
Circuit Descriptions
Base Circuit. Ignition Off. Cold Engine (Below 3 5 ' ~ )
A
positive feed
i s provided to the
R P M
relay.
Cold Crank. Below 3 5 ' ~
Oil
Temp.
When the ignition i s switched on, the Lambda sensor heating c o i l i s operated, and
the fuel by-pass control relay activated via the throttle position switch earth
circuit.
A n ignition feed i s also provided to terminal 15 of the rpm relay.
When the engine i s cranked, a negative signal from the ignition c o i l activates
the electronic control i n the
R P M
relay allowing the ignition feed to operate
the relay coil, and earth via terminal 31
.
The relay contacts now connect
the positive feed from terminal 30 to the fuel pumps via terminal 876, and to
the injection control circuit via terminal 87.
The injection control circuit supplies a positive feed to terminal 8 of the E.C.U.,
the frequency valve and the heating coils o f the auxiliary a i r valve and warm up
regulator.
The closed high temp. switch supplies the fast warrr up relay. See circuit
(3).
A
feed from the cold start contact on the starter motor solenoid supplies the cold
start injector which i s controlled by the thermal ti.ne switch.
Earth signals are supplied to terminals
12
and
6
of the E.C
.U.
via the low temp.
switch and fuel by-pass control relay (via i d l e changeover relay).
Cold Run
&
Idle. Below 3 5 ' ~
Oil
Temp.
Similar to circuit
(2)
except:
The cranking circuit feed to the thermal time switch and cold start injector i s
switched off.
The fast warm up relay, activated by the closed high temperature switch, provides
a n earth circuit for the ignition solenoid which receives a feed from the ignition
auxiliary circuit. The ignition solenoid operates the throttle jacking capsule which,
a t idle, prevents the throttle position switch 'closed' contact closing. N o earth
signal
is
supplied to E.C
.U.
terminal
6.
Cold Run
&
Idle. Above 3 5 ' ~
Oil
T e m ~ . Below 70°C Water Temp.
Similar to circuit
(3)
except:
Low temp. switch opers and cuts o f f earth signal to
E.C.U.
terminal
12.
Lambda
sensor operational.