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| Re: Vacuum line schematic [message #140658 is a reply to message #140625] |
Tue, 23 August 2011 15:47   |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
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Jay,
I'm looking at the picture you posted a link to. It is the one looking straight down at the carb. The hose that is running across the top of the fuel input to the carb is the Ported Vacuum hose that should go to the vacuum advance of the distributor. In the picture that hose is going to the vacuum advance through TVS first. The carb end of the hose goes on the highest port of the carb on the driver's side front.
I'm not sure I answered your question.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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| Re: Vacuum line schematic [message #140671 is a reply to message #140658] |
Tue, 23 August 2011 17:20 |
seven
Messages: 322
Registered: July 2008
Location: Calgary Canada
Karma: 0
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Senior Member |
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Thanks Ken
My question was answered by a nice gentleman off line with a simple picture and a simple explanation.
The ported vacuum connection is inactive until the throttle is
> opened beyond the idle position, then the ported vacuum and
> manifold vacuum become essentially the same
Great info guys
Jay Fox
Calgary AB
73 Painted Desert (Turtle)
78 Transmode (Trailer Donor)
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| Re: Vacuum line schematic [message #140674 is a reply to message #140625] |
Tue, 23 August 2011 17:38 |
fred v
Messages: 999
Registered: April 2006
Location: pensacola, fl.
Karma: 0
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from your web site it looks like you are up to you ears in GMC's. be aware of the somewhat limited hauling capacity of the GMC.
Fred V
'77 Royale RB 455
P'cola, Fl
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| Re: Vacuum line schematic [message #140919 is a reply to message #140625] |
Thu, 25 August 2011 12:26 |
PETEinLongBeach
Messages: 90
Registered: June 2007
Location: Long Beach, CA
Karma: 0
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Coincidentally, I also discovered a vacuum hose anomaly on my coach this week. While troubleshooting another issue, I discovered a carburetor vacuum nipple with no hose on it.
Looking down on the carb, it is a small vacuum nipple with a couple of bevels on it, on the front side of the carb, driver's side, and I think it's 2nd over from the left and down low. Not sure if I can get a decent picture of it. In maintenance manual X-7725, page 6M-2, figure 2, it might be "tube K", but it is difficult to be certain.
My coach is a '77 California model with 1 evap canister and vacuum throttle positioner. All vacuum and emissions systems appear to be hooked up, but perhapes I'm missing something.
Could this be an extra nipple for something my coach doesn't have? I'm not sure if the carb has been replaced by the previous owner.
Are there any other comprehensive vacuum diagrams besides what I'm finding in the factory maintenance manuals?
Pete Smay
Long Beach, CA
1977 Kingsley
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| Re: Vacuum line schematic [message #140928 is a reply to message #140919] |
Thu, 25 August 2011 13:23 |
C Boyd
Messages: 2629
Registered: April 2006
Karma: 18
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| PETEinLongBeach wrote on Thu, 25 August 2011 13:26 |
Coincidentally, I also discovered a vacuum hose anomaly on my coach this week. While troubleshooting another issue, I discovered a carburetor vacuum nipple with no hose on it.
Looking down on the carb, it is a small vacuum nipple with a couple of bevels on it, on the front side of the carb, driver's side, and I think it's 2nd over from the left and down low. Not sure if I can get a decent picture of it. In maintenance manual X-7725, page 6M-2, figure 2, it might be "tube K", but it is difficult to be certain.
My coach is a '77 California model with 1 evap canister and vacuum throttle positioner. All vacuum and emissions systems appear to be hooked up, but perhapes I'm missing something.
Could this be an extra nipple for something my coach doesn't have? I'm not sure if the carb has been replaced by the previous owner.
Are there any other comprehensive vacuum diagrams besides what I'm finding in the factory maintenance manuals?
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Sir: X7725 mm section 6 pages 4,5,6 This is emission control section. K goes to the canister on a single canister model. It also gives the routing for the Calif dual vacuum distributor.
C. Boyd
76 Crestmont
East Tennessee
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