[[MWR]Blood]

Well, you have to kill the timer to make it stop.
https://sampwiki.blast.hk/wiki/KillTimer

pawn Код:

if(VehicleFuel[GetPlayerVehicleID(playerid)] >= 100.0) 
{
      VehicleFuel[GetPlayerVehicleID(playerid)] = 100.0;
     KillTimer( RefuelingVehicleTimer[playerid]);
}