Hello .... I have a 2004 suburban LT with the 5.3 Vin code T engine (no flex fuel). I am getting pulse at the injectors, 55psi fuel pressure but no spark when removing boot and testing. I am seeing 12volts at the 4 pin connector on the coil and no blown fuses.

Recent changes were a new crank sensor and entertainment system wire short fixed. Worked for a few days after that and then after sitting over night it won't start. No codes and using scan tool I am seeing 130 rpms when cranking.

Any ideas?

 

Take a look at the engine/fuel electrical schematic on BBBind.com.
Give you something to go on as far as verifying voltages/grounds.

Given injectors are pulsing CKP signal to PCM probably good.
Verify PCM sig pulses to coils are there.
If sig pulses good but coils don't fire verify coils common voltage/grounds