Will not start after running out of gas?

You may not have put in enough gas. First, see if you can hear the hum of the fuel pump for one second when you turn on the ignition switch. Sometimes you can't, but they're usually pretty loud on GM trucks.

Next, try spraying some starting fluid into the air intake hose or air filter box. If all that's wrong is lack of fuel, the engine should run for a few seconds on starting fluid.

If you hear the pump running for one second, and the engine runs on starting fluid, put at least five gallons of gas in the tank. I learned this on my Grand Caravans. My '88 model has a bowl in the middle of the tank that the fuel pick-up screen sits in. That prevents fuel from running away when going around corners or during hard acceleration when the fuel level is low. During normal operation, a lot of fuel is pumped to the engine, then most of it goes through the fuel pressure regulator, then back into the tank where it flows up a ramp around that bowl. That flow draws in additional gas to keep the bowl full.

The point of this sad story is when the tank is run empty, and you add gas, it dumps right into that bowl. A quart of gas is plenty to get the engine restarted. The same is not true for my '94 model. On that one, the fuel misses the bowl and goes right into the main part of the tank. None of it reaches the fuel pick-up until at least five gallons is put in, then it overflows into the bowl and the engine will start. Once it's running, the entire five gallons can be used up because, as I described, the fuel returning from the pressure regulator keeps the bowl full as the level in the tank drops to nothing.

If the extra gas doesn't help, don't add too much more in case you have to drop the tank and replace the pump. Electric fuel pump motors are cooled by the gas. Sometimes when run empty, they can overheat and warp the motor's housing to the point it won't run, or it runs too slowly.

Let me know what you find and we'll figure out where to go next.

When you run out of gas, it can take the fuel pump out, here is how to check the fuel pressure to confirm, plus if you go over this video it will show you how to "bump" the bottom of the tank which can sometime bring the pump back to life for a last run.

https://youtu.be/lXLJbuAZ4CE?si=a-O7ke60bzXE_YCG

and

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Here is how to change the fuel pump out in case you need it. Check out the images (below). Please let us know what happens.

Okay, see if you can follow the video and bap the bottom of the tank to see if it comes back to life which will confirm the fuel pump failure.

Also be aware you should not hear the fuel pump running with just the ignition switch turned to "run" except for that first one second. The engine must be rotating before the pump gets turned on again. If you do hear it run for one second, after cycling the ignition switch a few times, that should be enough time for it to build normal pressure, then do the pressure test Ken described.