While I turn the car cuts off

I can't claim to be a Chevy expert, but there are a few things that can be checked:
1. Fuel pressure. If you have a partially blocked fuel line, you could get starvation at times.
2. Vapor lock. If your fuel line comes anywhere near the exhaust, or other place it can get heated, you can get intermittent cutting out.
3. Electrical loose connection. Low voltage to coil packs could simply be loose or corroded, causing intermittent spark.

Testing and monitoring of these will be a pain, and certainly your dealer isn't equipped to do that. Most dealers only know to replace whatever part the computer identifies as "bad". As many times as it takes to make you go away...

"runs bad" doesn't mean anything to a parts replacer.

Ignition timing would not change with the engine temp.
I'm going to assume the check engine light is not on when the engine is running, otherwise you would have checked the computer for trouble codes. And I'm sorry you dumped so much money in parts trying to fix it before troubleshooting it first.
The two things that come to mind based on your description are low fuel pressure or a problem with the EGR valve. Did the friend check base fuel pressure with the engine cold and warmed up ?

replace your fuel filter, and air filter ! you mean your fuel pump turns on , correct ? how do you know this for sure ? check all fuses, and especially GROUNDS ! ground wires get overlooked , and they should'nt . without them, you got nothing !!! tune-up lately ? replace spark plugs & wires ! distributor cap & rotor . oil change lately ? do it ! spark plug wires get old, hard, and crack, causing them to short out ! check all vacuum lines, if you have a throttlebody, tighten the mounting bolts, they do get loose !

run the fault codes first
indicates either injectors/low fuel pressure or crank/cam position sensor problem

this sounds like the carburetor is dirty internaly and needs a rebuild to correct the problem.if it was the fuel pump it would not matter if you held the pedal wide open or not it would not pump gas.you mention plug wires but not mention spark plugs specifically.these are the items that are normally replaced when a tune-up is done.plugs,cap rotor,points,condensor,plug wires if needed,air filter,fuel filter,set point gap,set ignition timing,adjust carb mixture.

Hello and welcome to FixYa!

Please do check the spark plugs as well. If the spark plugs have big gaps, corroded, covered with carbon or just faulty, it can cause fuel cut off. This is caused by fuel flooding and there's not enough current to burn the fuel. Do check the spark plugs and replace if necessary.

Another thing that can cause this issue is when the plug wires are worn out. If the plug wires are worn out, the current tends to jump which may cause current supply irregularities. I strongly suggest that you check and replace the plugs wires too.

Hope this helps and thank you for using FixYa! Have a good one!

Could be a slow IAC motor when cold.Try holding your foot down 1/4 of an inch when cold starting,if it starts quickly,then it is most likely is a gummed up/defective idle air control motor.I would like to see the engine coolant temperature sensor readings also.

You have to be more specific. It could be a number of things. What year is the vehicle? First thing you need to do is check for trouble codes.Your vehicle may have a faulty sensor. example(map, maf,crank sensor)...

when was the last time you replaced the plugs and wires? also check the fuel filter as it may be clogged.

You guys are having an ignition misfire. Start by replacing the plugs, (ONLY use NGK plugs on a Japanese vehicle. There's a reason Bosch plugs are so cheap)  and gap them correctly. If you have a cap and rotor in your distributor, replace them, too. If that doesn't do it, check the plug wires for cracks, scoring, or arcing (will look like chalk dust).
After all that, check the wiring from the coil and the coil itself. It could be something as simple as a corroded contact that needs to be cleaned.
Good luck!