Bump starting a diesel is a whole different experience, If its electronic you do need some voltage for the PCM. On the older machanical injection pumps you need just enough voltage for the fuel shut off on the injection pump. Now the fun part is you need to be on pavement to break it loose after dropping the clutch (skidding tires)and you need to be pulling it because it will take 20-30 ft of dragging it after it starts to compression fires and tries to run. Use lots of chain because you will run into the tow rig. We have only had to this in extreme cold. In the summer if you can't boost I would not recomend the above from experience.