Yesterday it'd occured again.

As above it stopped as i ran on the road at slow speed but this time it can't started for awhile. After stucked on the jammed traffic road for 1 hr. the technician came to me. Finally he got the gasoline cable off and found no oil but only air. The fuel in tank about 20 L.He said that right tank's empty and 20 L. in the other. Then i bought gasoline and add into the tank 70 L. Then after second start it's come .
I assume some problems for fuel injection system.
-fuel motor pump and fuse ----> technician told OK
-charcoal filter
-gasoline filter
Can anybody help me think? Please
-Are there something else?
-Which 're the most causes?
-how can i find fuel pathway diagram?
Thanks