unsigned long timer=0;
int state=1;

void setup() {
  // put your setup code here, to run once:
Serial.begin(115200);
}

void loop() {
  // put your main code here, to run repeatedly:

if(timer<millis())
  {
  switch(state)
    {
    case 1:
     Serial.println("Glühkerze ein");
     timer=3000+millis();
     state++;
    break;

    case 2:
     Serial.println("Lüfter Stufe 1 ein");
     timer=3000+millis();
     state++;
    break;

    case 3:
     Serial.println("Dieseleinspritzung starten");
     timer=1000+millis();
     state++;
    break;

    case 4:
     Serial.println("Lüfter Stufe 2");
     timer=3000+millis();
     state++;
    break;

    default:
     //alles über state 4 tut nichts
    break;
    }
  }
}