AIR LEAKS:
It is important that no air leaks exist anywhere in the
ex
haust system, before or after the sensor, as this will cause false
read
ings
. This will lead to poor engine performance, including misfires,
and the inability to properly auto-tune the EFI. Continued running of the
system with an exhaust leak can create detonation and possible severe
engine damage.
Incorrect installation of the sensor, exhaust leaks,
and any resulting damage is not covered by the
FiTech
manufacturer's warranty. It is very important to ensure your exhaust
is leak-free. For optimum EFI operation and function, your exhaust (on
the sensor side) must be totally secure with no leaks.
Installing the Wiring Harness
When installing the harness, the external ECU can be mounted any-
where in the engine bay or through the firewall. Be sure to keep it
away from excessive heat. The harness is made up of the following
connections: MAP, IAC, O
2
, TPS, CTS, fan, tach, injectors, ground,
positive connection to the battery, ECU, hand-held controller con-
nection, fuel pump, and key hot.
MAP
( Manifold Absolute Pressure)
Below -
Starting with the MAP sensor, the MAP is attached to the
outside of the throttle body on the passenger side. It regulates the
inlet air temperature and the manifold absolute pressure. The two
sensors (inlet air temp and manifold absolute pressure) are combined
for ease of installation. The Temperature Manifold Absolute Pressure
measures the load on the engine and will range between 10 and
90kPa while the engine is running. When the engine is off it will read at
99-100kPa. See Figure 8 below.
IAC
(Idle Air Control)
The Idle Air Control
Sensor gets installed
directly into the throttle
body. It is used to con-
trol the RPM of the
motor at idle. See Fig-
ure 9, above right.
TPS
(Throttle Position Sensor)
The Throttle Position
Sensor’s purpose is to
record how far the
calibration of the sensor
but, if the TPS reading is
not at 0 at idle then the
sensor needs to be
recalibrated. See Figure
10.
CTS
(Coolant Temp Sensor)
The Coolant Tempera-
ture Sensor cable plugs into a supplied sensor fitted into the manifold.
It is used to measure the temperature of the engine coolant. The
sensor then sends the information to the ECU to adjust fuel.
See Figures 11 and 12 on the next page.
Figure 7
Handheld
Controller
ECU
Ground
Fan
Key Hot
Fuel
Pump
Injector
connector
IAC
TPS
CTS
MAP
Tach
Fuel Pump Relay
O
2
Sensor
To Positive
Terminal
of Battery
4
Figure 10
Figure 8
throttle blades are open.
The ECU maintains the
Figure 9
