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#75612 03/29/2007 5:21 AM | Joined: Mar 2006 Posts: 14 New Guy | | New Guy Joined: Mar 2006 Posts: 14 | I can't seem to get my vacuum more than 14 (?) on the gauge. so I decided to test for leaks. I used a vacuum guage to test the vacuum advance by connecting it to the hose from the distributor and "sucking" the vacuum advance. The advance does move but the gauge loses vacuum over 2-3 seconds. Does this mean that the gauge is bad or is this normal. I am assuming that there is no leak in the line but I will check that next if necessary. I have not had the engine running since last fall. This is new rebuild so the engine should be ok. What tests would you do next to make sure vacuum is up to specs? | | |
#75613 03/29/2007 5:32 AM | Joined: Nov 2005 Posts: 6,100 'Bolter | | 'Bolter Joined: Nov 2005 Posts: 6,100 | Hy boerdoc, try running the engine with the distributer vacuum line disconnected and sealed and see if your vacuum comes up, I wonder if your advance diaphragm has a small hole in it, hope that helps. | | |
#75614 03/29/2007 12:59 PM | Joined: May 2005 Posts: 1,624 Shop Shark | | Shop Shark Joined: May 2005 Posts: 1,624 | An old trick is to spray choke or carb cleaner around possible places for vacumm lraks. Have the engine running and use the soda straw. When the engine rpm picks up you have found your vacuum leak.
Six volt guy living in a twelve volt world
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#75615 03/29/2007 4:28 PM | Joined: Feb 2004 Posts: 29,760 Kettle Custodian (pot stirrer) | | Kettle Custodian (pot stirrer) Joined: Feb 2004 Posts: 29,760 | Find someone who smokes (yeah, that's a major project, I know!) and have him/her blow a little smoke into the tube attached to the vacuum advance. Any smoke at all out of the housing is too much! replace the advance if there's any leakage at all.
Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!
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#75616 03/29/2007 8:56 PM | Joined: Sep 2001 Posts: 29,269 Bubba - Curmudgeon | | Bubba - Curmudgeon Joined: Sep 2001 Posts: 29,269 | Another version of beltfed's technique on a running engine is to lightly/barely open the feed on a propane torch, placing the head/spout near the intake manifold (near the manifold to head connections and near all the carb connections) and see if the idle increases. | | |
#75617 03/30/2007 3:16 AM | Joined: Mar 2006 Posts: 14 New Guy | | New Guy Joined: Mar 2006 Posts: 14 | Thanks for the help. Tomorrow I will test the advice given and I will post tomorrow night or saturday. | | |
#75618 03/31/2007 2:21 AM | Joined: Mar 2006 Posts: 14 New Guy | | New Guy Joined: Mar 2006 Posts: 14 | The vacuum advance was leaking. Thanks 3B Fortunately all other vacuum checks showed no leaks (carb cleaner test showed no changes) Thanks beltfed. When I get a new advance I will post the new vacuum readings.
Thanks to everyone | | |
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