Chevrolet Repair: 99 tahoe no fuel to injectors, crank sensor, noid light

Question
my son has a 99 tahoe with SFI system. I'm getting fuel to the fuel line next to the throttle body but no further. I can pour a little gas into the throttle body and it will run for a few seconds. This is the process I followed to determine the problem.
1. turned on the ignition switch and listened at the gas fill tube. = Pump noise for 2 seconds
2. poured gas into throttle body..=engine ran a couple seconds
3. replaced relay = no change
4. inspected all wiring relating to schematics=all good
5. removed fuel line at throttle body and turned ignition to on position for a second. = great flow of gas.
I am at a loss of why I'm not getting ANY gas into the throttle body or injectors..
What's your advice..
Carl

Answer
First check the inj fuse.
Then test the red or pink wire at the injectors with the key on, there should be battery power.
If there is, you might want to get a noid light, and connect it there, to see if there are pulses while cranking.
If not, the crank sensor may be the problem.

Van