| yet another fuel question [message #108796] |
Fri, 17 December 2010 20:49  |
RadioActiveGMC
Messages: 1020
Registered: November 2010
Location: Hot AZ desert
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Got my canister filter in today from JimK (it took one day to get, man he must of got it out the door in 10 secs after I hung up!)
Anyway, I know where the tank line goes on the canister filter.
Question is, can I go from the "carb" side on the canister filter and run the hose to the pcv valve vacuum line at the carb and "T" into it that line so the fumes will go into the carb?
***"Gettin There"-1973 23' Sequoia-
Michael, Onans smell, "Go solar/wind power!"
[Updated on: Fri, 17 December 2010 20:49] Report message to a moderator |
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| Re: yet another fuel question [message #108799 is a reply to message #108796] |
Fri, 17 December 2010 21:24  |
C Boyd
Messages: 2629
Registered: April 2006
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| Mr.RadioActive wrote on Fri, 17 December 2010 21:49 |
Got my canister filter in today from JimK (it took one day to get, man he must of got it out the door in 10 secs after I hung up!)
Anyway, I know where the tank line goes on the canister filter.
Question is, can I go from the "carb" side on the canister filter and run the hose to the pcv valve vacuum line at the carb and "T" into it that line so the fumes will go into the carb?
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Sir: The Q-jet has a designated port for this line. In the manual X7425 6M-3
"fixed idle air by-pass system is used.
In that the fuel tank will not be vented to atmosphere,
all fuel vapors are collected in a vapor collection
canister. A timed purge port is provided in the
carburetor throttle body above the throttle valves
adjacent to the off-idle discharge ports. The timed
bleed purge holes provide adequate purge to remove
all vapors that will be collected in the vapor canister .
They will bleed constantly during off-idle and part
throttle operation of the engine ."
Since I believe you said you had a Holly, maybe it also has a designated port for this also?? It should be the same size to fit the canister hose and should be marked??
While some people have put the canister vent other places, I don`t have enough learnen to reccomend T-ing into the pcv or not?? I might could see how a bad pvc and a bad vapor seperator could put gas fumes or raw gas in the crankcase and cause real issues?? I would think it would be better than nothing tho if the pcv and fuel seperator were working properly???
C. Boyd
76 Crestmont
East Tennessee
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| Re: [GMCnet] yet another fuel question [message #108800 is a reply to message #108796] |
Fri, 17 December 2010 21:23 |
jimk
Messages: 6734
Registered: July 2006
Location: Belmont, CA
Karma: 9
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You can, but the correct way is to hook up to the dedicated one
located on the front base just about 1 1/2 " left of the PVC one.
Has the correct hose barb for a 5/16 fuel/vapor line.
On Fri, Dec 17, 2010 at 6:49 PM, Michael <radioactive626@msn.com> wrote:
>
>
> Got my canister filter in today from JimK (it took one day to get, man he must of got it out the door in 10 secs after I hung up!)
> Anyway, I know where the tank line goes on it.
> Question is, can I go from the "carb" side on the canister filter and run the hose to the pcv valve vacuum line at the carb and "T" into it that line so the fumes will go into the carb?
> --
> 1973 23' Sequoia-
> Michael, Casa Grande, AZ
> _______________________________________________
> GMCnet mailing list
> List Information and Subscription Options:
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>
--
Jim Kanomata
Applied/GMC, Fremont,CA
jimk@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502
_______________________________________________
GMCnet mailing list
List Information and Subscription Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
Jim Kanomata
Applied/GMC
jimk@appliedairfilters.com
www.appliedgmc.com
1-800-752-7502
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| Re: yet another fuel question [message #108802 is a reply to message #108796] |
Fri, 17 December 2010 21:31 |
RadioActiveGMC
Messages: 1020
Registered: November 2010
Location: Hot AZ desert
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So on my Holly, I should look at the front of the carb. See where the pvc line goes, and 1 1/2" left of it I should have the ability to hook up the line from the canister if Im understanding correctly. It was dark when I was looking but I didnt see it first glance. Maybe I'll look harder tomarrow during daylight.
((PS: thanks jim, I was amazed the package got to me SO FAST on the busiest shipping week of the year!!))
***"Gettin There"-1973 23' Sequoia-
Michael, Onans smell, "Go solar/wind power!"
[Updated on: Fri, 17 December 2010 21:33] Report message to a moderator |
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| Re: [GMCnet] yet another fuel question [message #108805 is a reply to message #108799] |
Fri, 17 December 2010 21:34 |
jimk
Messages: 6734
Registered: July 2006
Location: Belmont, CA
Karma: 9
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Chuck,
Your correct, the PVC is a simple entrance below the throttle plate
while the vapor cannister connection has routing that does no go to
the area below the throttle plate directly.
I took a peak under a rebilt onjust now.
On Fri, Dec 17, 2010 at 7:24 PM, Charles Boyd <covered-wagon@comcast.net> wrote:
>
>
> Mr.RadioActive wrote on Fri, 17 December 2010 21:49
>> Got my canister filter in today from JimK (it took one day to get, man he must of got it out the door in 10 secs after I hung up!)
>> Anyway, I know where the tank line goes on the canister filter.
>> Question is, can I go from the "carb" side on the canister filter and run the hose to the pcv valve vacuum line at the carb and "T" into it that line so the fumes will go into the carb?
>
>
>
>
>
> Sir: The Q-jet has a designated port for this line. In the manual X7425 6M-3
>
> "fixed idle air by-pass system is used.
> In that the fuel tank will not be vented to atmosphere,
> all fuel vapors are collected in a vapor collection
> canister. A timed purge port is provided in the
> carburetor throttle body above the throttle valves
> adjacent to the off-idle discharge ports. The timed
> bleed purge holes provide adequate purge to remove
> all vapors that will be collected in the vapor canister .
> They will bleed constantly during off-idle and part
> throttle operation of the engine ."
>
> Since I believe you said you had a Holly, maybe it also has a designated port for this also?? It should be the same size to fit the canister hose and should be marked??
>
> While some people have put the canister vent other places, I don`t have enough learnen to reccomend T-ing into the pcv or not?? I might could see how a bad pvc and a bad vapor seperator could put gas fumes or raw gas in the crankcase and cause real issues?? I would think it would be better than nothing tho if the pcv and fuel seperator were working properly???
>
>
> --
> C. Boyd
> 76 Crestmont by Midas
> East Tennessee
> _______________________________________________
> GMCnet mailing list
> List Information and Subscription Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
--
Jim Kanomata
Applied/GMC, Fremont,CA
jimk@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502
_______________________________________________
GMCnet mailing list
List Information and Subscription Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
Jim Kanomata
Applied/GMC
jimk@appliedairfilters.com
www.appliedgmc.com
1-800-752-7502
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| Re: yet another fuel question [message #108807 is a reply to message #108802] |
Fri, 17 December 2010 21:44 |
C Boyd
Messages: 2629
Registered: April 2006
Karma: 18
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Senior Member |
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| Mr.RadioActive wrote on Fri, 17 December 2010 22:31 |
So on my Holly, I should look at the front of the carb. See where the pvc line goes, and 1 1/2" left of it I should have the ability to hook up the line from the canister if Im understanding correctly. It was dark when I was looking but I didnt see it first glance. Maybe I'll look harder tomarrow during daylight.
((PS: thanks jim, I was amazed the package got to me SO FAST on the busiest shipping week of the year!!))
|
Sir: It depends on which Holly you have?? It may or may not have a canister port. On the Q-jet the timed purge is tied in above the idle circuits so it only vents off idle. On some Hollys the idle circuits are on the sides.
Is your holly a spread bore or square bore with an adapter? Maybe post the carb # and We`ll try to research it for you?? Holly has about a zillion different carbs..
C. Boyd
76 Crestmont
East Tennessee
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| Re: yet another fuel question [message #108810 is a reply to message #108796] |
Fri, 17 December 2010 21:46 |
RadioActiveGMC
Messages: 1020
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Location: Hot AZ desert
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I'll have to see which one it is. I had a friend whos pretty good with carbs figure out which one I needed before he installed it.
If it doesn't can I do the pvc valve idea?
***"Gettin There"-1973 23' Sequoia-
Michael, Onans smell, "Go solar/wind power!"
[Updated on: Fri, 17 December 2010 21:48] Report message to a moderator |
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| Re: yet another fuel question [message #108814 is a reply to message #108810] |
Fri, 17 December 2010 22:20 |
C Boyd
Messages: 2629
Registered: April 2006
Karma: 18
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| Mr.RadioActive wrote on Fri, 17 December 2010 22:46 |
I'll have to see which one it is. I had a friend whos pretty good with carbs figure out which one I needed before he installed it.
If it doesn't can I do the pvc valve idea?
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Yes, but it will be a full time induced vacuum leak sucking fuel vapors at best. As the amount of vapors in the canister change it will also change your idle mixture accordingly. The pcv system is a hard pulling manifold vacuum even at idle. If you pull the pcv line off at idle creating a massive vacuum leak it will lean out usually to the point of killing the engine. The canister port only opens a limited amount of timed vacuum during off idle operation and does not effect the mixture under open throttle. At idle if you take the canister port off a Q-jet it has no effect, only at open throttle and then just a small amount to pull vapors.
A lot of the newer carbs do not have canister ports since they are made for builders and not for specific replacement.
Another seemingly alternative would be hooking to ported vacuum, but that is where the dist vacuum goes and would effect the ignition timing control cause you are adding a vacuum leak and adding fuel vapors to the diaphram on the dist advance unit. Not good.
C. Boyd
76 Crestmont
East Tennessee
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| Re: yet another fuel question [message #108815 is a reply to message #108796] |
Fri, 17 December 2010 22:31 |
RadioActiveGMC
Messages: 1020
Registered: November 2010
Location: Hot AZ desert
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Silly question then, if my carb has no port which I gave it a fast glance. On the back side of the carb it had two really small plastic rubber capped lines but they look really small, i didn't notice any other ports on the carb.
What happens if I just plug the vapor line?
***"Gettin There"-1973 23' Sequoia-
Michael, Onans smell, "Go solar/wind power!"
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| Re: yet another fuel question [message #108816 is a reply to message #108815] |
Fri, 17 December 2010 22:50 |
C Boyd
Messages: 2629
Registered: April 2006
Karma: 18
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| Mr.RadioActive wrote on Fri, 17 December 2010 23:31 |
Silly question then, if my carb has no port which I gave it a fast glance. On the back side of the carb it had two really small plastic rubber capped lines but they look really small, i didn't notice any other ports on the carb.
What happens if I just plug the vapor line?
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I would think the canister would fill with gas fumes and exit out the filter in the bottom of the canister to the engine compartment under the pass seat. Basicly the same thing as you had before you put the canister on. The canister is also the filtered vent for the fuel tanks and if plugged would not vent the tanks as designed.
Since the canister only needs a small amount of vacuum, but a fairly large volume, I would think that maybe if you tied it in under the airfilter housing inside the air filter it might pull enough off idle to clear the vapors and burn them as EPA designated.
I hope this helps..
C. Boyd
76 Crestmont
East Tennessee
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| Re: yet another fuel question [message #108832 is a reply to message #108796] |
Sat, 18 December 2010 09:47 |
RadioActiveGMC
Messages: 1020
Registered: November 2010
Location: Hot AZ desert
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I have a "hole" in the air filter outer housing that only has a 90 degree rubber elbow on it doing nothing. Its on the outer part of the air cleaner housing, can I maybe run my hose to it?
***"Gettin There"-1973 23' Sequoia-
Michael, Onans smell, "Go solar/wind power!"
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| Re: yet another fuel question [message #108835 is a reply to message #108832] |
Sat, 18 December 2010 10:12 |
C Boyd
Messages: 2629
Registered: April 2006
Karma: 18
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| Mr.RadioActive wrote on Sat, 18 December 2010 10:47 |
I have a "hole" in the air filter outer housing that only has a 90 degree rubber elbow on it doing nothing. Its on the outer part of the air cleaner housing, can I maybe run my hose to it?
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I don`t think a stock Q-jet air filter housing will fit most Hollys as to the end float bowls. If the Air filter housing is enclosed with an inlet snorkle it may? In the 455 left valve cover is a breather that is supposed to be ran to the air filter housing outside the filter. On some engines this sometimes pulls oil vapor into the air filter and blackens the air filter and restricts intake air. I would think gas vapors would get stuck in the filter also? I would rather have the fuel vapors inside the filter to be drawn directly into the carb. We are trying to get the fuel vapors out of the engine compartment and into the engine. I would probably try drilling a hole and rig a 90* (brass?) hose elbow in the housing inside the filter to hook the canister line to.
C. Boyd
76 Crestmont
East Tennessee
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| Re: yet another fuel question [message #108836 is a reply to message #108796] |
Sat, 18 December 2010 10:20 |
RadioActiveGMC
Messages: 1020
Registered: November 2010
Location: Hot AZ desert
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humm sure appreciate your help.
My airfilter housing on the drivers side has a 90 degree rubber elbow doing nothing really. The left valve cover has a pvc valve, and the right valve cover has a "breather" like the ones sold on jimk site. Maybe somehow I can figure out how to enter under the cleaner housing past the filter so it can be close to the carb. I'll have to see how I can do that. I thought the open vapor line I found would of been a easy fix, go figure! lol
Oh PS: I'm pretty sure my air cleaner housing is the original and fits perfect.
***"Gettin There"-1973 23' Sequoia-
Michael, Onans smell, "Go solar/wind power!"
[Updated on: Sat, 18 December 2010 10:22] Report message to a moderator |
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| Re: yet another fuel question [message #108838 is a reply to message #108836] |
Sat, 18 December 2010 10:56 |
C Boyd
Messages: 2629
Registered: April 2006
Karma: 18
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| Mr.RadioActive wrote on Sat, 18 December 2010 11:20 |
humm sure appreciate your help.
My airfilter housing on the drivers side has a 90 degree rubber elbow doing nothing really. The left valve cover has a pvc valve, and the right valve cover has a "breather" like the ones sold on jimk site. Maybe somehow I can figure out how to enter under the cleaner housing past the filter so it can be close to the carb. I'll have to see how I can do that. I thought the open vapor line I found would of been a easy fix, go figure! lol
Oh PS: I'm pretty sure my air cleaner housing is the original and fits perfect.
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Sir: The left valve cover (driver side) should be the engine breather hooked to the air filter and the right valve cover (pass side) should be the pcv valve. Maybe the engine builder got them crossed?? I think it makes a difference in the crankcase venting system cause of the direction of rotation of the engine. Possibly the 2 grommets are interchangable? and you can swap breather and pcv without removing the valve covers? Maybe somebody with more knowledge than me will know??
As you may already know, everstuff on the coach that is right or left is determined from the drivers seat.
So far you are doing good.. keep it up. It is refreshing to find a new owner willing to learn and do. Many years ago when I first lost my leg I had issues with mowing my grass and it would get pretty ragged. I found that if I went out and tried to push the mower almost instantly every neighbor I have would be there with their mowers helping. Even since with my riding mower, they still show up often with weed eaters helping. Remember "the only stupid question is the one you don`t ask."
C. Boyd
76 Crestmont
East Tennessee
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| Re: yet another fuel question [message #108845 is a reply to message #108796] |
Sat, 18 December 2010 13:49 |
RadioActiveGMC
Messages: 1020
Registered: November 2010
Location: Hot AZ desert
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I truely appreciate the help. And feel dumb at this point. After I looked really hard at the holly carb and a call to jimk I noticed there was a small 1/4" line left of the pcv valve that goes into the carb. Called jimk he told me thats the line for the vapor line. I went to napa bought fuel hose and my canister filter is now installed! My carb after all did have the nipple to install the fuel vapor line, I just never saw it!!!!!
THANK YOU SOOOOOOOOOOOO MUCH for the help!
Now I need to find if the left valve cover needs the breather or is it the right side.For sure my drivers side valve cover has the pcv valve and the right (passenger side) has the breather.
***"Gettin There"-1973 23' Sequoia-
Michael, Onans smell, "Go solar/wind power!"
[Updated on: Sat, 18 December 2010 15:55] Report message to a moderator |
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| Re: yet another fuel question [message #108855 is a reply to message #108796] |
Sat, 18 December 2010 14:43 |
RadioActiveGMC
Messages: 1020
Registered: November 2010
Location: Hot AZ desert
Karma: 0
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Yea I need a manual for sure...I'll switch them out later today...or next week.
***"Gettin There"-1973 23' Sequoia-
Michael, Onans smell, "Go solar/wind power!"
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