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post #1 of (permalink) Old 09-28-2000, 10:29 PM
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Evap canister

I was wondering if there is a way to temporarily disable or bypass the evap can. Mine is purging while idling---- wrecking havoc with the idle. Am getting a new one but it is a dealer only part $70 and special order (ie. pay upfront--get the part sometime next week). was wondering if you could just pull the purge line and plug it without causing other problems. Any help appreciated.

89 YJ 4.2 Carter bbd auto tranny

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post #2 of (permalink) Old 09-29-2000, 12:10 AM
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Re: Evap canister

Cap both the small VACUUM lines that go to the cap on top of the canister. Leave on the larger lines that go to the carb and tank.

post #3 of (permalink) Old 09-29-2000, 08:36 AM
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Re: Evap canister

I have always wondered how this thing is supposed to work. Can either CJDave or TeamRush or other Guru give a short lesson in evap can theory?

Thanks. Turtle

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post #4 of (permalink) Old 09-29-2000, 08:52 AM
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Re: Evap canister

[img]/wwwthreads_images/icons/blush.gif[/img] Everything that I know about emmissions I learned from CJ-8/5.2Mag.....[img]/wwwthreads_images/icons/blush.gif[/img] Marty was a valuable source of good information when we re-smogged our illegal, smogless, hot-rod CJ 304 V8. As I understand it, the charcoal in the cannister captures the fumes from the pool of gasoline in the fuel tank and from the pool of gasoline in the carburetor when your Jeep is sitting there not running and especially when the heat soak from a hard run is warming up the carb and the fuel tank now that the breeze from driving has stopped, and the heat is causing the gasoline to overheat and "gas off" like crazy. The fumes from the two pools of gasoline accumulate in the charcoal pack, and therefore don't fill up the garage and annoy your Jeepchick. ["Owwwww.....your Jeep STINKS!"[img]/wwwthreads_images/icons/mad.gif[/img]] When the engine is restarted, the purge valve receives a signal from the vacuum advance line, and that lifts the valve seat and allows intake manifold vacuum from the engine to suck the accumulated fumes out of the charcoal pack, mix them with the intake mixture, and make everybody oh so happy once again.[img]/wwwthreads_images/icons/smile.gif[/img] So you can see, that the cannister does not retard performance and is actually a benefit. THERE IS ONE CAUTION......cannisters CAN cough up charcoal into the vacuum system, so a fuel filter in the purge line is a darn good insurance policy. A clear filter would even be better so you can SEE if it is happening.[img]/wwwthreads_images/icons/smile.gif[/img]Oops!..[img]/wwwthreads_images/icons/blush.gif[/img]....that should have been a fuel filter in the CARB BOWL VENT LINE......not the purge line.[img]/wwwthreads_images/icons/blush.gif[/img] The idea was to keep charcoal out of the carb bowl.[img]/wwwthreads_images/icons/crazy.gif[/img]

Quadra-Tracs modified While-U-Wait by the crack moonguy[img]/wwwthreads_images/icons/wink.gif[/img] Quadra-Trac Team.[img]/wwwthreads_images/icons/tongue.gif[/img][img]/wwwthreads_images/icons/smile.gif[/img]
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post #5 of (permalink) Old 09-29-2000, 09:42 AM
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Re: Evap canister

Very helpful. Thanks CJDave!


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