Where does pcm pick up injector pulse on cranking? Crank or cam sensor? I have an intermittent no/long crank before it starts. I just varified it was injector pulse now finally. It was sparking but no pulse then as soon as the noid light started flickering it lit off.
I also tried unplugging the cam sensor and it still will start and run. I dunno if running off the crank is a default or not.

 

It references the cam sensor, the ecm commands the injector to pulse when a cylinder is on the intake stroke. Details of your setup?

 

Really?
The LS1/LS2 cam sensor only has one pulse per cam rotation.
I have forgotten to connect the cam sensor, and while the car then has trouble starting, once started it runs perfectly.

I do believe that the 24x (or 58x) pulses per crankshaft revolution from the crank sensor are used to time the injectors and the coils.

 

24x Cam sensors will typically start with cam unhooked. It's just a long crank

 

It uses the crank sensor for timing and fuel. If the cam sensor us unplugged it will still run. On cranking it may take longer than normal until the PCM sees the sync pulse, then it starts normally.

As long as there is spark there should be fuel pulse. If it doesn't then you have other issues like security or wiring.