Problem starting like its not getting gas

Spark may not b strong enough or float level/fuel pressure wrong. Air cleaner or leak in a gasket. Test batt n starter for strength. Compression cud b bad

I have never seen a gas additive that was "thick". You may have plugged a fuel filter. Should be a cheap and easy replacement to try.

New fuel pump springs to mind ?

if it's a diesel, it needs to be bled of air before it will start. If it's a gas engine, make sure you've got a few gallons in the tank because not enough gas is getting to the pump. you could try start spray or carburetor cleaner to get it going and the gas might start circulating. take the air filter cover off and spray some into the tube towards the motor and it will start

Sounds like a fuel pump issue but could be many other things too. I would start by replacing the fuel filter, it's possible its not letting in as much fuel as needed. Spark plugs are another possibility, I'd change them out if they're more than a year old (as your car gets older it will blow more oil and the spark plugs get fouled much sooner). It could be compression too, you'll need to pressure test each cylinder and verify compression is within spec (if it's not, that's a BIG repair). Also try lower octane gas, it actually ignites faster than high octane gas.

Did you check for spark? It sounds like you're not getting spark. Check for spark. If you are not getting spark then it sounds like you might have to replace the coil packs. Is it running a L4 engine? If its running a standard chevy L4 its probably the coil packs. Try to replace them check again for spark.

Your gas could be bad from sitting for 4 months. If you can get it started again, try running the gas down as low as possible and fill up with 90 octane (premium) gas and a can of gas treatment. This is the easiest thing to check 1st. If it continues, could be your fuel pump going bad.

maybe its bad gas, or an idle issue. you shouldnt have to pump the gas when you start that can actually lead to flooding the engine with gas. Turn the key on and wait about 30 secs before cranking this will ensure your getting proper amount of gas to injector lines. It may take a bit to get rid of gas in there but keep doing it until it starts properly. Also note in doing this do not continuously crank it as the starter and solenoid will fry. Also if you fear there is no gas going to engine look for a gas line bleeder valve. Looks like a tire valve head and usually is covered with a black plastic lid. If you push it in and gas squirts out then your getting gas to engine. If you release all gas and turn the key on and test gas line again and no gas comes out then its what is called a dry start, aka no gas getting to motor. Hence failure of fuel filter or fuel pump. Or a general clog in gas line.

You pinched the fuel line????
If you crank for too long to start the car, the engine will "flood", this is why the plug was wet. It had too much gas and wouldn't start.
Pull out ALL plugs and dry them off.
Install them.
HOLD your gas pedal to the floor and crank.
This will stop gas from entering the engine.
you need to get that extra gas out beofre it will start.
If you have so much gas in there you can do damage to your engine!!
Now after a few crnaking attempts with your foot to the floor, take your foot of the gas pedal and try to start it again.
But remember if it doesn't start in 3 tries, you need to do the pedal to the floor once or twice to remove the excess gas.
When you crank the car to start it sprays gas into the engine, even if it won't start. So it very easy to "flood" the engine, and then you'll have a hard time to get it going!

You will need about 2 gallons of gas to get the car started. Also have the front of the car lower than the rear. I have had the problem with mine. If I am low on gas, I get the car on a downhill slope, and it starts right up and I get straightaway to the gas station.