in your case, what was done to the car while it was broken down
resulted in the bleed off of the held fuel pressure.
The guy with the starting fluid could purge the fuel system, or try adding his own fuel to the air intake.
In this case he used starting fluid. it is not IN the system currently.
It fired the engine and was spent and sent out the exhaust.
Now that your fuel pump is enabled because the lack of spark has been fixed, the injectors have purged and deliver fuel uninterrupted and there is held rest pressure, you can expect it to function normally.
If you used aftermarket parts for the ignition module, save your receipts and be aware they tend to fail more often than an OEM part in many cases.
(you said the car did not want to crank)
You must have meant it would crank but would not fire.
Since adding fuel by way of the spray made it start.
So the air purged. the system primed, and the cause was cranking it with no pump operating, as a result of no spark.
Plugged fuel filter and or low fuel pressure. Change the fuel filter first. Take the car to a Chevrolet dealer and ask then to test the fuel pressure on the fuel rail pressure fitting. This is a very inexpensive test BUT the fuel filter must be clean to get an accurate fuel pressure reading. The dealer will know what the fuel pressure should be.
Some cars get all wonky about not working correctly. I had a 1984 Nissan that would not restart after ignition failure unless I used starter fluid, just about like your experience except after it had been running a minute or so it was okay. It sounds like you are out of the woods.
Starter fluid lasts only a few minutes before it evaporates . Your car is starting on its own now .
Sounds like it cranked to me. Don't know the difference between cranking a motor over and when it starts? When a motor doesn't crank you either have a dead battery, bad cable connections, or a seized up motor.
He did it to keep the motor running long enough for the fuel system to pressurize. Sounds like he has somewhat of a clue as to how things work.
Get a new car
I would say your fuel pump is sluggish and your mechanic doesn't want to change it.
Okay so my car had a bad ignition module. We got a new one on and the car still didn't want to crank so my mechanic sprayed some starter fluid into something under the hood and I started the car and it stayed on for a minute and then died. He did it again. And kept spraying until eventually the car stayed on. That was last night and it has been turned on and off several times and it turns on fine. Is this because my car is fixed or because there is starter fluid in the system? Also why did we need started fluid to get it going if we put a brand new part on it? 2000 Chevy cav.