Hesitates when driving, doesn't start first time, reeks of fumes when tank full & caped, engine cuts out when gas cap removed under half tank full. dummy light me always on. please help me TY

MOVE THE CAR FAR AWAY FROM HOUSES AND KIDS AND PEOPLE NOW. PRONTO

NO YEAR CAR TOLD OR COUNTRY . 2.7L OKAY.
WRECKING THE CANISTER LIKE THAT IS SUPER BAD.
THAT CAUSES HUGE GAS TANK PRESSURES FOR GO CRAZY HIGH. THE CAR IS DANGER TO YOU AND ALL AROUND YOU
NOW. IT WILL CATCH FIRE, AND IT WILL NOT BE A HAPPY DAY.
GLAD I AM FAR FROM YOU.

RAW LIQUID FUEL COMES TO THE CANISTER ONLY 2 WAYS.
THE BAD BOY THAT DID THAT ACT
OR OVERFILLING THE GAS TANK.
OR BOTH, I BET BOTH. (OR HOSE ON THE TANK BOYBOY WRECKED THOSE TOO)
FIND A REAL SHOP TO FIX ALL THAT OR HAVE BAD FIRE.
IF SOMEONE DRIPS A CIG NEAR YOUR CAR IT WILL NOT BE FUN. EVER.
EVAP 101
Nomally the tank is never full, ever. by design at the filler the station pump clicks off at full , do not overfill any cars tank.
at that moment the tank has and air space on top, and only fumes are there, not gas.
these fumes are sent to a check valve (evap) to the canistor
and it collects only fumes never ever gas,raw, and if did the raw gas wrecks the canister carbon brick inside.
when you run the engine the engine vacuum sucks the fumes out of Mr. canister and it is now fresh and clean, and repeats.

your car is now HACKED and unSAFE.
find a shop to UN HACK it.

You may have a defective vapor recovery system or a loose hose coupling between the filler and the tank. The recovery system can go bad after a lot miles/time. Also, overfilling the tank (going beyond 'one click') can damage the system.
I would replace the gas cap first, make sure it is the right kind, before having the VR system checked.

Well it could be numerous if things but you want suggestions...So here's mine..Your gas tank might be vapor locked...This is caused from over filling your gas tank with gas over the years..Its when the pressure in your gas tank becomes greater than your fuel pump. It wont start until the pressure in your gas tank becomes lower then you fuel pump...Sounds crazy...This got me once...I didn't understand it...A lot of people (including me) Go to the gas station and get that extra 50 cent after the gas nozzle clicks off...over time that extra gas will run down the vapor lines intended to burn fumes....Like when you fill a gas can to cut your grass...If you sake the gas can it builds pressure and bows up. But with time that pressure will go away...Well saying that...Your gas tank needs to vent to....So your car burns not only gas but fumes...If you keep over filling your car with the extra gas it cloggs up your vapor canister intended for fumes or vapors...The gas will will go into that canister and clogg up the charcoal that's inside it. (Breaks it down) then the vapors can't get to your carburetor where it supposed to burns it. So what happens is the pressure in the gas tank becomes greater than your fuel pump and then car won't start..Are you with me? Lol Its crazy..Putting a different gas cap can cause the same thing...Simple test...When you open your gas cap to get gas.. Do you heat air sucking in.. Yes you can hear it....A lot of times loosening the cap let's the pressure out and the car will start right up.....Thus might not be your problem but worth telling at the gas pumps to other people..... Just trying to help

sounds like the fuel gauge is off
how many miles can you go on the 1/2 tank of gas

you can unhook the fuel line, from the fuel rail(Under the hood), place hose into gas container, unhook starter solenoid(So the car doesn't crank). and hold the key in the "start" position, untill the container is full!

NOT going to recommend it, OR suggest it... it can be VERY dangerous, having raw fuel/fumes sprayed over the engine!

Check the:
1 Cylinder compression/ valve clearance.
2. Ignition system.
3. Spark plugs.
4. Fuel pump pressure.
5. Injectors.

in the EVAP system
it is possible that the fuel has got into the cannister and you are smelling the fumes from the vent

Obviously you have something above the tank that's leaking. That will result in a code the same as a bad or loose gas cap. At this point, the only way you can find the source is to take a good look at everything, even if it means dropping the tank to do that. (better than wasting fuel or having a fire start under there).

normally fumes come in to vehicle when stopped because of oil leak from rocker cover but check your fuel filler cap seal etc and also incase the tank is leaking just have a sniff at the rear of the car if its the filler cap or tank filler you normally get smell when tank is nearly full and been around a few corners the fuell filler nect becomes pourous and just spills out a bit if so will need replacing .but most time its an oil leak from rocker box or engine

fuel tank vent could be blocked by mud/pebbles etc, not letting the gas fumes escape while your adding fuel making it overflow, check underneath the car near the fuel tank .. something to start with..