Leaking Chevy
Puzzler time.
This one is automotive. Here we go.
Many years ago, one of my guys was under the hood of an old Chevy pickup truck trying to find a vacuum leak.
Now, a vacuum leak is a leak which allows air to get into the engine when it shouldn't be getting into that spot, and specifically into the combustion chamber.
All the air that enters these old engines should come either through the carburetor, if the car has one, or through the throttle body. And any air that comes into any other source is called a vacuum leak, and it affects the way the vehicle runs. If the leak is sufficiently large, the thing won't run at all, or it certainly won't run it idle, and it'll stall out every time you take your foot off the gas.
And that's exactly the problem that this vehicle had.
The way you find vacuum leaks is you either you get lucky and you hear the hissing are able to pinpoint the problem that way. Or we used to use a little wand that shoots propane. And you go around with this wand attached away, the other end of which is attached to a propane tank, and you squirt this propane all over the place, and when the vacuum leak and the propane meet, you'll suck the propane in, and the engine will begin to run smoothly. If you take it away, it runs lousy again.
So there he is with the wand, and he's having lousy luck under the hood looking for this leak. The vehicle is running, but the leak is so big, it's the leak is so pervasive and yet so evasive that he can't seem to find it.
So in desperation, he throws this stuff down and he shuts off the engine.
And a few minutes later, I walk by and I see him doing something very interesting. He's pulling off the spark plug wires, and he's putting them back on, but on the wrong plugs.
Two minutes later, I hear him on the phone ordering the part that he needs to correct the vacuum leak.
How did he do it?
Good luck.