GxT Ferret 63 DIAGNOSTIC ENGINE ANALYZER - Manual (Page 13)

“FUEL INJECTION” KEY
Injector solenoid pulses and sensor sig-
nal frequency are read by these tests
through the red Auxiliary Clip.
SOLENOID DUTY & HERTZ
Use Solenoid Duty on mixture controlled carburetors, or
frequency output sensors such as some pressure and
air flow sensors. Also use this test to check Hall-effect
switches. "Hz" should go up and down directly with
changes in RPM, and "DUTY" should be constant within
a few %. "DUTY" is usually about 50%.
The term "DUTY" means the portion of time that the sig-
nal is switched to ground, which is when power is applied
to solenoids, etc. Duty is not shown for signals over 60
Hz. Frequency up to 250 Hz can be read.
SELECT changes the scaling of the "DUTY" reading for
either:
milliSeconds (mS DUTY)
Percent (% DUTY)
degrees / 60 (Dg M/C)
The lower left reading shows averages of the longest and
shortest duty. If the numbers match, the duty is steady.
If there is a difference, the signal pulse width is vary-
ing which may mean that there is active control (closed
loop), or if it should not vary it could be a defective signal
source or connection.
The "M/C" display changes to "LEAN" if the readings are
over 50, and "RICH" if less than 10.
FUEL INJECTOR
Press FUEL INJECTION and SELECT Fuel Injector mil-
liSecond readings.
Hook the Auxiliary Clip to the injector driver wire.
The detector is made to read the time that current flows
in a solenoid by watching the voltage drop from the 12V
battery level.
When engine RPM is run up and down quickly, "Min" and
"Max" hold the shortest and longest milliSeconds pulse
widths while the center reading shows what is presently
happening. START is used to reset the "Min" and "Max"
readings. Up to 63 milliSeconds can be measured.
SENSOR
TEST
02 TPS
SETUP AMP ZERO SELECT MESSAGE
PRINT
DISPLAY
PRINT
AUTOTEST
CHARGING
STARTING
AMPS VOLTS
IGNITION
PRIMARY
COIL MODULE
DWELL VARIATION
AUXILIARY AUXILIARY PER CYLINDER
CRANKING
ANALYSIS
COMPRESSION
BAT. STARTER ALT.
POWER
BALANCE
% RPM DROP
AUTO MANUAL
PER CYLINDER
SPARK
BURN
SECONDARY
MSEC SLOPE
PER CYLINDER
HARD
START
IGNITION VOLTS
AUXILIARY
FUEL
INJECTION
MSEC, % DUTY, HZ
AUXILIARY
START
PAPER
ADVANCE
-11-
640 RPM Bat 14.06
0.8Min 1.7mS 6.5Max
REGULATED CURRENT INJECTOR SIGNAL
PULSE
mSec
Shortest
Pulse
GND
B+
640 RPM Bat 14.06
28>31 % DUTY Rate 10 Hz
SELECT: Solenoid Duty
TEST then START
ACCELERATION DECELERATION
RICH VARYING LEAN
BAT
GND
OFF
ON
0° 10° 15° 30° 45° 50° 60° DG M/C
MIXTURE CONTROL CARBURETOR DWELL RANGE
0° 25% 50% 75% 100% DUTY
SELECT: Fuel Injector
TEST then START
PULSE
DRIVER
SIGNAL
BATTERY
VOLTS
Connections are reversed
on different engines.