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Troubleshooting
Testing the coil pack for spark (4 & 8cylinder) Caution high voltage!
The easiest test if the CPi2 unit is installed is to use the COILTEST function in the
Hidden Settings area. This will send test signals out all channels of the CPi2 to the coil
pack(s) connected.
Dual board CPi2’s, Press the PROG key to switch to the “B” ecu and use that Coiltest
function to test the second coilpack for sparks.
Disconnect plug wires from engine spark plugs and place wires ends close to ground
with a small gap to see the spark jump. You can also use spare spark plugs as shown
in the photo. Note how wire and plugs are connected in this photo to pairs of 2 spark
plugs clamped together. Never test for spark by just removing the plug wires
.
Spark plugs
We recommend resistor type spark plugs only. Non resistor type may cause electrical
interference.
Verify firing order of the engine. Double check plug wire routing and cyl numbering.
Spark plug wires
,
and Interference Problems
Always use radio suppression type spark plug wires. NEVER use solid core wires.
Recommended wires:
Magnecor, MSD superconductor, NGK, OEM or factory carbon string, Accel 8.8 yellow.
Troubleshooting continued
Excessive RPM drop when doing Runup test, AKA MAG CHECK:
1. Different timing in A and B ecu’s.
2. Check timing with a timing light on both coil packs to confirm timing is correct and if timing is equal on both coil
packs.
3. Swapped hall sensor cables going to A&B ecu’s. Check green and red connector colors where hall sensor
connectors plug into the ecu. Green should be closest to the ecu lid, red closest to mounting flange. Did
someone unplug wiring and plug it back into the cpi2 with hall sensor plugs swapped?
4. Fouled bottom spark plugs. Check spark plug condition.
Will not power up.
1. Check 2A fuse on side of ecu box.
2. Check for +12V on Purple wire of Main harness 14 pin plug.
Will not start:
1.
Check power and ground connections. Two grounds on a single board CPi2 and four grounds on a Dual board
CPi2. Look for unconnected black wires.
2.
Check Hall sensor alignment. Double check wires at the 4 pin connector at the CPi2, they may have been
inserted wrong.
3.
No sync magnet being seen by the CPi2 unit. Check TRIG SYNC window and make sure all magnets are being
seen. Without at least 1 sync magnet pulse the CPi2 cannot begin to make sparks occur.
4.
Check # OF CYLS setting for 4,6,8 cylinder to make sure it is correct for the engine. If you cannot find this
screen using arrow keys, then find the SHOW HIDDEN SETTINGS screen and change this to YES, then scroll
using the left arrow key
5.
Check for a Trigger magnet that registers as a Sync magnet. This indicates that the Trigger magnet is installed
backwards so the wrong polarity is facing the hall sensor. This magnet would need to be removed and a new
magnet installed in its place.
6.
If aircraft type key/mag check switch is connected, check connections to yellow and gray wire and check the
ground connection to the mag switch. Disconnect yellow and gray and try starting again.
7.
Check firing order and spark plug wires. Cylinder numbering on Lycoming and Continental engines is different.
See supplement manual for more information.
