Smoke tester
Smoke tester
(OP)
I have noticed that some emission control smoke testers warn against using a supplied air source to test for leaks within the fuel system. They are afraid that the oxygen, as low as it is in air, with ignite some how with the fuel and blow up the car. They recommend an inert gas like argon. But lets see, in a modern emission control system the ccv valve opens up to to allow AIR to enter in the system to evenetualy purge into the intake. Not to mention, isn't air composed of 78% intert nitrogen.





RE: Smoke tester
the tank. Especially on all those old airplanes with recip engines, there is no saftey valve that is keeping all that air out of an aircraft fuel tank. And besides what is that funny stuff that goes spuhhhhh when you losen that gas cap at the station?
Must be argon huh???? I'm sure glad they never put a "vent" to let air in a gas tank in the old days. Yeah I'm being funny.
RE: Smoke tester
Did you ever notice the effect on the engine when a bug plugged up that "nasty" air intake?
B.E.
The good engineer does not need to memorize every formula; he just needs to know where he can find them when he needs them. Old professor
RE: Smoke tester
RE: Smoke tester
Certainly pulling a vacuum seems safer and effective.
Regards
Pat
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Soooo... air is 78% nitrogen, which means it won't sustain combustion? For some reason I thought air was a more effective oxidizer than pure nitrogen by a large margin?
RE: Smoke tester
Quick education:
http://www.autoshop101.com/forms/Hybrid13.pdf
I dont think it would create a sustainable combustion but there are alot of factors like its now under about 14 lbs of pressure from the smoker air source. Hence my question here.
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I can't cite the configuration of every car in existence off of the top of my head, but the ones I've looked at do not draw air into the tank intentionally as part of testing for leaks - the closest they do is draw a slight vacuum and monitor the recovery rate.
I thought a smoker worked by boiling mineral oil and mixing it with a cool gas to condense and disperse the resulting vapor, not by burning the oil? That process would create "oil fog" rather than "smoke" and would not rely on the presence of oxygen.
If you feed "smoke" into the intake manifold and it manages to waft into an evaporative emissions control line to reveal a leak, no problem. I would not recommend connecting those lines directly to compressed air to force air + oil fog into the evap system.
RE: Smoke tester
read the manual I attached.
Also watch the video:
https://www.youtube.com/watch?v=zsTDUdWylFU
Notice that the smoke comes out of the fuel cap, hence its in the tank, evap port to tank.
It burns....they use a wick and a nichrome wire:(patent)
http://www.google.com/patents/US7305176?pg=PA1&...
RE: Smoke tester
When you're purging the cannister, you don't have to route the purge air through the fuel tank.
"It burns....they use a wick and a nichrome wire"
really? Then why do they have a paragraph at the very end of the smoke pro brochure describing how to drain excessive condensed "smoke" back into a reservoir? Read the patent you linked to. They never mention burning the fluid, but they make repeated references to vaporizing it. They also mention that one of the primary methods of operation of smoke machines is to completely submerge the heating element in the "smoke fluid." That pretty much eliminates the possibility that those ones are burning anything.
If all you hope to get out of this thread is someone's blessing to go and do what you're apparently determined to go do (blow pressurized air into a fuel system and see what happens) then just make sure your kids aren't home before you do it, and have fun! If there is some other point to all of this, I'm missing it.
RE: Smoke tester