Start with a full tune-up, including an oxygen sensor and air filter. My '93 323 also gets bad gas milege. I averaged only 25 mpg on a trip to California. Maybe it's part of being an old car now, but I will also check the fuel filter. I meant fuel tune up and oxigen sensor and all that stuff.
Fuel consumption in a car is based on factors like the shape and weight of the car. Toyota and Honda are both car brands which consume less fuel.
No you will actually save gas. It works pretty good actually.
1.5 to 2.0 km/lt
Many are heavy cars with powerful engines. It takes fuel to move them.
Jet fuel is high grade diesel so a jet fuel car would use high grade diesel fuel.
installed wrong or bad fuel pump
it depends on how it is made and what size car it is in.
Yes, directly proporiate to weight. A 2500lb car will consume half the fuel of a 5,000lb car
fuel pump or fliter
dirty fuel line
What i think that the fuel pump in your car could not be working properly. In other words, its not sending enough fuel to the cylinders to start the car. If that is what is wrong.
It seems like you're running too rich of a mixture - too much fuel, and not enough air.