Plugging in the block heater makes no difference.
that's completely odd.....WHEN BLOCK HEATER PLUGGED in you should have zero issues...
EOT = 90°F when IAT = FREEZING OR BELOW.
CHECK YOUR ENGINE BLOCK HEATER?
can you see the voltage drop on the meter when the GP are on?
.....increase when they turn off?
GPIL = 6 seconds (a joke indicator light)
GP ON time = 84 seconds at IAT = 38°F, EOT = 45°F
voltage will go from 12 v to 11.4 volt when GP ON
then jump up to 11.88 or so when GP turn off.
I have done as many as 5 FULL GP BURNS 84 SECONDS EACH.......
at 40°F or below and using my cold start tune no problems.
although at freezing/8000' on trips I stay plugged in for 3 days if I can!
have a propane generator for powering the block heater if no grid power
Depends more on fuel mixes .....??
NOT ALL DIESEL IS CREATED EQUAL!
i COULD cold start better before changing injectors, removing EPBV, FUEL BOWL/HEATER......going efuel
..also have all new GP/BIG RELAY, rebuilt alternator
so i have today arriving some fuel filter heaters!
will install and test and post results...