Try putting fuel injector in the gas tank. Should be directions on the bottle but think you only need one per full tank of gas.
Some of your spark plugs may not be working, go and see a mechanic soon, my car has had similar problems the mechanic said if we didn't go sooner the car was going to run on 2 cylinders.
what kind of car is it
Supercharger
Your car is making a funny noise while going downhill accept when pressing the gas because your car has all them teeth and no toothbrush! Also your car is a piece of crap and needs to be replaced with a better one. If I had to bet, I would say you are driving an american made car, more specifically, a Chevy. hahahaha chevy is the worst car company in the world!
A person pressing the gas pedal.
Possibly a hose is broken or disconnected on the crankcase ventilation system?Intake Manifold?
Torque converter maybe. To test, while pressing gas peddle lightly push on brake and if it stops then bingo! bad converter
shaking jerking when pressing on gas
press the break and call the car company you bought it from.
Pressing on the gas pedal sends more gas to the combustion chamber for the combustion process which sends more pressure to the engine for your car to pick up speed.
The voltage is lacking when you are not pressing on the gas... while pressing on the gas.. you are giving the headlights more electricity...
possibly cam sensor
Possible vacuum leak.