2000 GMC Sierra with vortex motor will start with starting fluid but dies immediately

your ambient air temperature sensor isn't workin'

Use caution using starting fluid in a vortex motor. If it backfires thru the intake you will be replacing the intake. The intake on a vortex is plastic. And how do I know this I blew mine have way across my back yard.

When mine did same it was the fuel pump bad. Check fuel pump.

...but dandyoun, if the pump were bad would not continue runnin-...man, my head is still in the dinosaur era when we had a "stove kit" heat diverter and heat riser and butterfly valve...all this hardware has been replaced by one such "mosquito biscuit" (as it has been lovingly named) the computer wants to know whats up, whats down, and what's goin' on all around this town...what temperature is such an important little goodie that it replaces the butterfly, heat riser and stove kit....inextricable....dude, modern times~

it would need some fuel pressure, perhaps you are right, but in my experience it's curtains...kaput and no more commander...would not see ANY action only with the go go juice~

I understood that it would start with starting fluid but dies immediately. I took this to mean that it would run only while starting fluid was being sprayed into it and would die when no starting fluid was being used. That seems to me to mean that no fuel is getting to intake. Possibly bad fuel pump. But again I advice that no one use starting fluid on a vortec engine. Spider tubes(as I call them) in plastic intake will get damaged. Only fix is to replace intake if that happens.

fuel pumps aren't that much just a bit of a fashion to put in~

The ambient temperature sensor is for the display on the rear view mirror.

I agree with dandy, if you are having to spray "fuel" into the engine to make it run then obviously the engine isn't getting fuel, since it runs that means it's getting spark so it's not the crank sensor. Check your fuel pressure.