Should all injectors fire when key is on truck not running?
 

I need help

zero injectors will be firing then. they wont fire till they see a specific amount of pressure. i think its around 5 kpsi

So what does it mean when i have two firing with ignition on only

You mean when cranking right? If the injectors are firing with the key on not running your ECM is fryed! Replace the harness, check the plugs to the harness?!

Afraid of that

Are u 100% injectors on a 03 5.9 diesel never fire without rotation of motor?

The injectors wont fire unless they have enough fuel pressure. The cp3 won't make any fuel pressure when the engine is not running. Do you think yours are firing?

Not true. With the engine not running or starter engaged and the key on, injectors #1 and #6 will cycle constantly to bleed the pressure out of the rail. ECU programming controls that.

how is there rail pressure if the truck hasnt been started? not fully understanding what you are saying here

Pressure will hold in the rail when the engine is shut down and the injector solenoid does not cycle. Keeps the potential for air getting into the system lower. When the key on sequence is detected the ECU cycles 1 injector on each bank.

When the cranking circuit is engaged there is a timeout that stops injectors cycling so the rail pressure can build. It takes 2 full engine revolutions to synch the cam and crank sensor so the CP-3 is spinning 3 times as many to build pressure. The purge routine is easily fit into the crank and synch before the engine actually fires.