[DinFtown]

I have used starting fluid countless times, and never had a problem. Don't go run your car so it is red hot then do it, I mean use some commen sence about it. If you are leaking spark out you wires, well then that is sad, and you might want to fix that. Like I said the only way to do it is with something flamable... du. do not use propane(although propane is a great way to clean all the carbon deposites out of your motor. I use fumigation on my cummings, it's great) it will sink in air, and sit in your engine compartment making for a nice setup for a explosion, the starting fluid is a liquid, and it evaporates(the flamable part) the evaporation goes up into the air out of you engine compartment. Just use starting fliud, you do not need much, it is very noticeable when you spray near a leak. If you are still worried about it, take it to you mechanic and have him perform a smoke test, or if you have a smoke machine just use that(it is alittle more dificult on a 911 motor but it works).
Dave