Accent 2001 won't start after driving for only 100km

Fuel capacity:62 liter / 16.4 U.S. gal / 13.6 imp. gal

ECE 90/120/city (comb.):
6.2 / 7.9 / 10.8 (8.3) l/100km
45.6 / 35.8 / 26.2 (34) mpg (imp.)
37.9 / 29.7 / 21.8 (28.4) mpg (U.S.)
16.1 / 12.7 / 9.3 (12) km/l

Fuel consumption simulation based on the European type of traffic:

extra-urban / city / highway / average combined:

l/100km: 7.2-8.6 / 11.1-13.3 / 8.6-10.3 / 9.5
mpg (imp.): 32.7-39.2 / 21.2-25.5 / 27.4-32.8 / 29.7
mpg (U.S.): 27.2-32.6 / 17.6-21.2 / 22.8-27.3 / 24.7
km/l: 11.6-13.9 / 7.5-9 / 9.7-11.6 / 10.5

Driving range - (km / miles on tank)
extra-urban: 715-860 km / 445-535 miles
city: 465-560 km / 290-345 miles
highway: 600-720 km / 370-445 miles

average combined: 653 km / 405 miles

The tank holds 65 litres. You should use 18 l/100km in city and 12 l/100km on road - that gives you a standard autonomy of 360 km in city and 550 km on road.
270 km is far too little - even if you would drive only thru a very congested/gridlocked city.

Could be, or it could be you TPS sensor(Throttle Position Sensor)

That fuel consumption is a bit heavy, but not excessive, depending on the driving conditions. In heavy traffic and slow town driving with a lot of stop starts it would be acceptable but on the open road in 2 wheel mode it would be excessive. Kia do not seem to manage much better than about 8-10 l/100km, even on their sedans.

According to the book:

City Driving: 7.65 km / Litre (13L/100km)
Highway Driving: 11.48 km / Litre (8.71L/100km)
Combined Driving: 8.93 km /Litre (11.2L/100km)

Hope that helps!

You should replace your timing belt every 60,000 miles or every 96,560 km in your case.

well the first thing you need to do is to pull the stored codes in the computer and see what they say and then go from there, this could be a speed sensor or a trany going bad , i dont know if this is an automatic or standard trany, start with the codes from the check engine light, autozone car parts store will scan the computer at no charge,

No It is not. But you may want to consider a transmission filter service. But first check for any trouble codes for the drive train system

That sounds like the "Porportioning valve" is defective.
You may want to go to your local library and check out a Chilton's, or some other repair manual for the "how to" to fix yourself or take it to a tech you can trust.

have the front wheel bearings checked.