GxT Ferret 63 DIAGNOSTIC ENGINE ANALYZER - Manual (Page 28)

BASIC TEST
At test completion the ignition will be enabled momen-
tarily to sense the Spark Pickup on cylinder plug #1. The
display will show:
Stop cranking.
As soon as the spark is detected the engine should
stop.
The analyzer looks at the data to check for irregularities,
followed by this display which shows peak amps for each
cylinder.
If "msg" appears, press MESSAGE. In this test MES-
SAGE also displays the last Cranking Analysis messag-
es. Passing the last saved message or pressing START
returns the display to showing test data.
Press START to see the percent lower-than-the-highest-
cylinder amps. Readings over 10% indicate an unusual
cylinder.
The display is arranged by firing sequence.
(top: 1,2,3,4; bottom: 5,6,7,8).
If more than 8 cylinders are tested the data will be shown
in sets called "Bank A" and "Bank B", which are the first
and second halves of the firing sequence. Press START
to see both.
Pressing START additionally displays the last Cranking
History data. The displays recycle.
TEST VARIATIONS
The saved measurement data is first analyzed for consis-
tency. If it is too irregular the display may show a blank
and there will be the following messages:
This may be caused by a battery that weakens during the
test, or it could be from a type of engine starter that has
interfering vibrations.
If the spark plug signal is absent the data results will not
be synchronized with the engine, but can still give an
indication of cylinder compression uniformity.
If there is a cylinder with 10% lower amps this message
will be shown:
Note that the temperature and friction of the engine af-
fect the amperage. A very hot or cold engine, or one
that has new piston rings and bearings may draw higher
than normal starter current, thus tending to cover up the
compression variations in the current.
Some users have found that some engines needing an oil
change can show large variations in peak amps. Normal
peak-amps are restored with fresh oil.
STEP THREE
Engine Data Unsteady
RESULTS UNUSABLE
Cylinders not in Sync.
No SPARK PICKUP Signal
Low COMPRESSION Likely
Check with Gauge
-26-
(CRANKING PEAK-AMPS)
THE ENGINE MAY START DURING THE TEST
STOP CRANKING
AMPS pk 190 200 164 188
/CYL msg194 182
AMPS % 5 0 18 6
LOW msg 3 9
WARNING