User Manual

To Connect to the Fuel Injector
1. Connect the Inductive Pickup around the single battery
supply wire going to the coil or module. Confirm the
pickup is facing the proper direction by selecting the
Drive Time function. If Drive Time is full scale at Idle,
the Pickup is on backwards.
Measurements
1. Peak Amps is the peak current driving the coil. It is
regulated by the module. A typical Peak Amp reading
should be about from 5 to 10 amps.
2. Build Time, or ramp time, is the time it takes the
amperage to reach its maximum.
3. Drive Time is the time the coil is actively driven.
Analysis of Test Results
If Peak amps is low look for a bad connection between the
module and coil. Long Build Time may be caused by high
resistance in the connection from the ignition module to
the coil. Short Build Time may be caused by a shorted
coil. Build Time will be slightly longer during cranking.
Using the Primary Ignition Probe with a Labscope
The 72 sends a signal that is scaled at .1 volts (or 100mV)
per amp detected. A 4 amp peak will appear 0.4 volts high
on the labscope. Use a BNC Cable with a BNC to Banana
Adapter (like Ferret P/N W090-10) to adapt the 72 to work
on most labscopes or graphing multimeters.
Engine/ Peak Build Engine/ Peak Build
Company Amps mSec Company Amps mSec
Chrysler 3.3L 5.0 4.0 GM-2.0L 8.0 3.0
Chrysler 3.5L 5.0 4.0 GM-2.2L 9.0 3.0
Chrysler 3.8L 5.7 3.8 GM-2.3L,(Quad 4) 8.0 2.5
Ford 1.9L 5.0 3.1 GM-3.0L 6.5 3.8
Ford 3.0L 5.0 3.5 GM-3.1L 10.0 2.8
Ford 3.8L 5.0 3.5 GM-3.8L (Type I) 7.0 3.8
Ford 4.0L 5.0 3.5 GM-3.8L (Type II) 9.5 3.0
Ford 4.6L 5.5 3.3 Saturn 1.9L 7.6 3.3
Technical Support
For additional information or technical assistance, please
contact Ferret Instruments at [phone] or
www.ferretinstruments.com.
OPERATOR’S MANUAL
Primary Ignition Probe 72
FEATURES
Test ignition coils and modules
without piercing wires or
backprobing connectors. Can
be used on Distributor, DIS, Coil
near Plug and Coil on Plug
Ignitions.
Use a LabScope to view the fuel
injector pattern.
20 segment bar graph displays
Peak Amps, Build Time or Drive
Time at the press of a button.
Find defects in ignition coils
and modules by using current
ramping measurements.
Powered by a 9 Volt battery.
3 Year Limited Warranty
www.ferretinstruments.com