When the engine was shut down, if the car is making pit stop, the technician must start the car. Can LFS make the car can start again in pit?

except for the bf1, all cars have startermotors iirc...
at least all the roadcars, and probably the gtr's too

All the cars except the BF1 would be mandated to have a starter motor in there real world parallel series. The single seaters would not have an alternator though so they would be severely limited in the number of starts they can manage without a slave battery, normally 2 or 3 tops.