2003 hpdi 175 no fire on #6 coil

[dellisj68]

had a problem with fire on only 1 4 and 5 cylinders replaced crank sensor and started firing on all cylinders except cylinder # 6 switched coils from one that was firing with # 6 still didn't make any difference cleaned all grounds and checked all computer connections still not firing on # 6 cylinder

[rodbolt17]

what method are you using to test spark?
CPS has nothing to do with spark production on HPDI.

[dellisj68]

using an inline spark checker that has a light that flashes also used a clip on one that has an adjustable gap

[rodbolt17]

you can test the ign coil primary voltage.
its a 12V transistor switched system.
at key on you should see 12V from red to ground.
then slip a paper clip nto the connector black wire.
use a jumper lead and rapidly strike to ground.
you should see spark.
if so test the ground path for continuity to the ecu.
if you lose a pulser coil you lose spark on that cylinder and fuel is fixed by signals from the CPS and TPS.
timing will be fixed at 7*BTDC and idle speed increases and top speed cannot be reached.

the transistors in the ECU act as a set of points, just like grannys old chebby.

[dellisj68]

thanks for the information checked for voltage on connector to # 6 coil it only had 3.7 volts on hot wire with key on checked others and they had battery voltage what else should I check

[rodbolt17]

find the poor connection on the power supply on #6.
see how simple this is?
hint, don't go towards the ECU.
that is not the issue.
ign coil voltage,like the fuel pump, comes off the main relay and goes to a gang junction connector.

[dellisj68]

thanks rodbolt u the man checked for bad connection on fuse holder but had a broken wire in the harness took a while to find but thanks for the input