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Unread 07-22-2004, 06:16 AM   #1
MudMonster
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Join Date: Jan 2003
Location: Ft. Mitchell, KY
Posts: 610
vacuum leak???

ok we'll start with the facts, theres a whistling sound coming from the engine bay, it goes away when i unplug the vacuum advance on the dist. I assume this is a leak i just cant find it, any advice on this? I dont know jack about the vacuum system so can i just unplug it cause it drives me nuts, how important is the vacuum advance?

btw i leave on a road trip friday night, so itd be nice to fix this b4 that

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Unread 07-22-2004, 07:31 AM   #2
jadams68
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The vacuum advance on CJ's advances the timing depending on the temperature of the motor. When cold the advance get it's vacuum from the manifold and when warm gets it from a ported vacuum source.


Try this trick... get a propane torch, turn the gas on and move the end around your motor while it's running. If you hit a vacuum leak, the engine RPM's will spike from pulling in propane and you've found your leak.
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Unread 07-22-2004, 02:59 PM   #3
jode
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Propane never worked for me for some reason, but if the leak is already audible, stick a piece of 1/8" to 1/2" hose in your ear and move the other end of it slowly around the engine compartment. You should be able to find the leak VERY easily in this manner.
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Unread 07-22-2004, 03:07 PM   #4
MudMonster
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yeah propane didnt work, i even took the advnce hose off and let it suck on the propane and it didnt work
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Unread 07-23-2004, 11:03 PM   #5
Jeepbeeper
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Quote:
Originally Posted by MudMonster
yeah propane didnt work, i even took the advnce hose off and let it suck on the propane and it didnt work
lol....
you have to turn on the can of propane first ..FULL open ok.
sheesh..
it will not blow up..jadams is right...its the only quick way
to find that leak.
OR...you can take a needle nose pliar, and pinch off the hose AT the point it plugs into the male receiver .
the hose being female...and the receiver the hose slides onto...the male..
if this does not work...then you arn't looking close enough.
Disabeling the vaccume advance will assuradly cause poor
acceleration and horrible consequenses to plugs foweling
at some point in y our trip.
Take the time to look closer to the hose conditions.
cracked or spongy hoses can collapse and shut off needed
mechanical workings...ie: choke full open control, and
cause your vehicle to bog upon acceleration.

check behind the carb..there may be one male appiture some hose leads to...that may be your culprit...so look closer.
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