I would not use gasoline, use starter spray, it evaporates more readily and it will start the engine if only for a moment. Gas will puddle. It evaporates much more slowly and the vapor trail, if ignited can follow it to the sprayer. Don't use gasoline!
The horror stories about starter spray are generally unfounded unless you spray a bunch in. If used as intended, it won't harm the engine if used sparingly.
Bigger question is: WHY do you think you need to do this on a fuel injected engine?? Are you testing if its getting fuel? Or spark? Because it won't do either, it will make the engine run for a moment not telling you anything.