Toyota COMPUTER-CONTROLLED SYSTEM Training Manual page 73

EFI - Fuel Syste m
10 . COLD START INJECTOR ELECTRICAL
CIRCUITR Y
CONTROLLED BY START INJECTOR TIME
SWITC H
When the engine is cranked while the engine
coolant temperature is low, the duration of cold
start injector operation is controlled by the start
injector time switch .
ST terminal
CONTROLLED BY ECU (STJ CONTROL )
In order to improve startability when the engine
is cold, the injection duration of the cold start
injector is controlled not only by the start
injector time switch but also by the Engine ECU
in accordance with the coolant temperature .
Control of the injection duration of the cold start
injector continues to be carried out by the start
injector time switch, as shown by shaded area A
in the figure below, but control is also exercised
by the Engine ECU, as shown by shaded area B
in the figure .
Engine EC U
STA STA
OHP 5 1
I
-20 0 20 40 60
(-4) (32) (68) (104) (140 )
Coolant temperature °C (°F )
On or off depending on engine model
OHP 51
U
N
N
C
6-
0
co
4-
C
0
a
0
i
2-
-S
0
STJ I I STA
A, B
-20 0 20 40 6 0
(-4) (32) (68) (104) (140)
Coolant temperature °C (°F )
A: Controlled by start injector time switch
B : Controlled by EC U
A, B: Controlled by sta
rt
injector time switch and
ECU
OHP 5 1
63