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Jeff67sqbk
Samba Member
Joined: October 18, 2004
Posts: 35
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 Posted: Tue Sep 18, 2018 7:58 am Post subject: 67' Dual Carb Idle Too High |
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'67 Sqbk, stock dual Solex carbs. Just rebuilt motor (by AVP).
Set carbs at the defaults, 1/2 turn idle, 1 1/2 turn mixture screws.
Idles at about 900 RPM.
Checking carb flow with Unisyn reveals that left carb flow significantly more than right.
Adjusted left carb as low as it can go (then adjust mixture) still 900 RPMs.
Can adjust right carb (then adjust mixture) to match left flow brings idle to 1100 RPM.
Not sure what to change or adjust now to get idle lower.
Jeff '67 Sqbk stock
Nevada City, CA |
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sqbk1971
Samba Member
Joined: October 27, 2016
Posts: 134
Location: Dallas, Texas
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| Posted: Tue Sep 18, 2018 10:24 am Post subject: Re: 67' Dual Carb Idle Too High |
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| I had similar issue after rebuild. Have you tested for vacuum leaks around manifold and head. I found that the shape of my manifolds did not seal well with generic metal gaskets that comes in a standard engine rebuild kit. |
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Bobnotch
Samba Member
Joined: July 06, 2003
Posts: 22425
Location: Kimball, Mi
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| Posted: Wed Sep 19, 2018 8:59 am Post subject: Re: 67' Dual Carb Idle Too High |
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| Jeff67sqbk wrote: |
'67 Sqbk, stock dual Solex carbs. Just rebuilt motor (by AVP).
Set carbs at the defaults, 1/2 turn idle, 1 1/2 turn mixture screws.
Idles at about 900 RPM.
Checking carb flow with Unisyn reveals that left carb flow significantly more than right.
Adjusted left carb as low as it can go (then adjust mixture) still 900 RPMs.
Can adjust right carb (then adjust mixture) to match left flow brings idle to 1100 RPM.
Not sure what to change or adjust now to get idle lower.
Jeff '67 Sqbk stock
Nevada City, CA |
You might want to have a look at this thread.
https://www.thesamba.com/vw/archives/manuals/t3dualcarbtuning/index.php
It goes into detail about dialing in the carbs. It might also help you find your problem.
Also, never use the metal gaskets for the intake manifolds commonly found in the standard "complete" gasket kits. This is mostly because they don't seal very well, and have a tendency to loosen up with time (causing leaks). They also transfer heat into the intake manifold.
I hope this helps.
_________________
Bob 65 Notch S with Sunroof
71 Notch ...aka Krunchy; build pics here;
http://www.thesamba.com/vw/forum/viewtopic.php?t=249390 -been busy working
64 T-34 Ghia...aka Wolfie, under construction... http://www.thesamba.com/vw/forum/viewtopic.php?t=412120
| Tram wrote: |
| "Friends are God's way of apologizing for relatives." |
| Tram wrote: |
| People keep confusing "restored" and "restroyed". |
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DQDan
Samba Member
Joined: October 24, 2016
Posts: 351
Location: Cleveland OH
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| Posted: Wed Sep 19, 2018 4:00 pm Post subject: Re: 67' Dual Carb Idle Too High |
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"Also, never use the metal gaskets for the intake manifolds commonly found in the standard "complete" gasket kits."
I'm getting ready to bolt up two 32PDSIT's on my 66 build and was going to use those metal crush washers at the base of the intakes. What do you suggest as substitutes? TIA |
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Bobnotch
Samba Member
Joined: July 06, 2003
Posts: 22425
Location: Kimball, Mi
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| Posted: Thu Sep 20, 2018 8:12 am Post subject: Re: 67' Dual Carb Idle Too High |
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| DQDan wrote: |
"Also, never use the metal gaskets for the intake manifolds commonly found in the standard "complete" gasket kits."
I'm getting ready to bolt up two 32PDSIT's on my 66 build and was going to use those metal crush washers at the base of the intakes. What do you suggest as substitutes? TIA |
Thick paper gaskets available from good VW parts suppliers like CB Performance, Air Cooled.net, and others. I think the last set I used were Bug Pack gaskets.
_________________
Bob 65 Notch S with Sunroof
71 Notch ...aka Krunchy; build pics here;
http://www.thesamba.com/vw/forum/viewtopic.php?t=249390 -been busy working
64 T-34 Ghia...aka Wolfie, under construction... http://www.thesamba.com/vw/forum/viewtopic.php?t=412120
| Tram wrote: |
| "Friends are God's way of apologizing for relatives." |
| Tram wrote: |
| People keep confusing "restored" and "restroyed". |
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Erik G
Samba Member
Joined: October 16, 2002
Posts: 13280
Location: Tejas!
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| Posted: Thu Sep 20, 2018 9:08 am Post subject: Re: 67' Dual Carb Idle Too High |
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and if you need it in a hurry, your flaps will have gasket material by the roll. They may actually have the gaskets too, you'd be surprised. For beetles and buses, the "heater hose" from autozone is great from the shroud to the heater box. better than the crap at the VW shop
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Jeff67sqbk
Samba Member
Joined: October 18, 2004
Posts: 35
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| Posted: Thu Sep 20, 2018 8:55 pm Post subject: Re: 67' Dual Carb Idle Too High |
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I replaced the manifold and carb gaskets with proper paper style ones tonight.
My local VW FLAPS, Parts for Imports, had the thick paper manifold gaskets, and I cut the carb gaskets from gasket material.
It still runs rich in the left carb.
Looking down into it I can see liquid fuel in the the left carb, whereas in the right one I don't see any liquid.
Closing the mixture screw didn't change it at all.
Thoughts?
Jeff '67 Sqbk stock
Nevada City, CA |
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Erik G
Samba Member
Joined: October 16, 2002
Posts: 13280
Location: Tejas!
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| Posted: Thu Sep 20, 2018 9:06 pm Post subject: Re: 67' Dual Carb Idle Too High |
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Check you floats (one may have a hole) the needle valves, float height, fuel pressure
I think you probably have a stuck needle valve or a float that ain't floating. You can shake it and hear it, or weigh it. Or put in gas and look for bubbles
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Bobnotch
Samba Member
Joined: July 06, 2003
Posts: 22425
Location: Kimball, Mi
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| Posted: Fri Sep 21, 2018 1:42 pm Post subject: Re: 67' Dual Carb Idle Too High |
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Agreed, check your float and needle and seat valve on the left carb. It sounds like the float isn't sitting right allowing fuel to continue to dump when it should stop the flow.
The needles and seats (for the float) are known to cause problems too. If you still have the old ones, put them in and try it again.
_________________
Bob 65 Notch S with Sunroof
71 Notch ...aka Krunchy; build pics here;
http://www.thesamba.com/vw/forum/viewtopic.php?t=249390 -been busy working
64 T-34 Ghia...aka Wolfie, under construction... http://www.thesamba.com/vw/forum/viewtopic.php?t=412120
| Tram wrote: |
| "Friends are God's way of apologizing for relatives." |
| Tram wrote: |
| People keep confusing "restored" and "restroyed". |
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Jeff67sqbk
Samba Member
Joined: October 18, 2004
Posts: 35
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| Posted: Sat Sep 22, 2018 10:00 am Post subject: Re: 67' Dual Carb Idle Too High |
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Float floats, no holes and moves freely. Replaced float valve and no change. Still too much fuel getting through.
Jeff '67 Sqbk stock
Nevada City, CA |
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Jeff67sqbk
Samba Member
Joined: October 18, 2004
Posts: 35
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| Posted: Fri Oct 12, 2018 8:38 pm Post subject: Re: 67' Dual Carb Idle Too High |
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Update. I replaced the left carb with another I had hanging around. It is a 32PDSIT instead of the 34 that was installed.
Same exact problem with this carb too! Too much fuel getting into the left head.
As someone suggested it might be high fuel pressure, so I swapped the fuel lines left to right hoping that there might be an obstruction.
No dice, same problem, again. Maybe I'll have to try the other spare carb I have. |
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W1K1
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Joined: March 04, 2004
Posts: 4921
Location: Southern AB
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| Posted: Sat Oct 13, 2018 5:48 am Post subject: Re: 67' Dual Carb Idle Too High |
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put a gauge on it to find out what the fuel pressure is. too much pressure will push past some needle valves. some stock pumps can put out 7-10 psi when you only need 2.5psi
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1973 super
1965 squareback 1500E
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Bobnotch
Samba Member
Joined: July 06, 2003
Posts: 22425
Location: Kimball, Mi
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| Posted: Sat Oct 13, 2018 11:32 am Post subject: Re: 67' Dual Carb Idle Too High |
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Yup, like I mentioned to Monte, use paper pump to bakelite gaskets to lower fuel pressure.
_________________
Bob 65 Notch S with Sunroof
71 Notch ...aka Krunchy; build pics here;
http://www.thesamba.com/vw/forum/viewtopic.php?t=249390 -been busy working
64 T-34 Ghia...aka Wolfie, under construction... http://www.thesamba.com/vw/forum/viewtopic.php?t=412120
| Tram wrote: |
| "Friends are God's way of apologizing for relatives." |
| Tram wrote: |
| People keep confusing "restored" and "restroyed". |
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Jeff67sqbk
Samba Member
Joined: October 18, 2004
Posts: 35
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| Posted: Wed Mar 06, 2019 2:58 pm Post subject: Re: 67' Dual Carb Idle Too High |
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I swapped floats around and the amount of fuel flowing at idle was reduced.
I added paper gaskets to the fuel pump and now I don't see any fuel dripping into the carb looking down inside while running.
However even with the idle screw not touching at all, the lowest idle I can set is about 1200 RPMs.
According to the Unisyn, the left carb is still the source of the extra fuel.
What is the next step to try and get a reasonable idle? |
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Mike Fisher
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Joined: January 30, 2006
Posts: 17970
Location: Eugene, OR
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| Posted: Thu Mar 07, 2019 2:31 pm Post subject: Re: 67' Dual Carb Idle Too High |
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It's probably maladjusted rods. There is a procedure for setting them All in proper order Correctly. 
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66 sunroof,67,70,71,71,71AT,72,72AT,73 Parts
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'68 Karmann Ghia sold
Society is like stew. If you don't keep it stirred up you end up with a lot of scum on the top! - Russ_Wolfe/Edward Abbey |
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Bobnotch
Samba Member
Joined: July 06, 2003
Posts: 22425
Location: Kimball, Mi
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| Posted: Thu Mar 07, 2019 3:32 pm Post subject: Re: 67' Dual Carb Idle Too High |
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| Mike Fisher wrote: |
| It's probably maladjusted rods. There is a procedure for setting them All in proper order Correctly. |
Yup, see the link I posted near the top of this thread.
_________________
Bob 65 Notch S with Sunroof
71 Notch ...aka Krunchy; build pics here;
http://www.thesamba.com/vw/forum/viewtopic.php?t=249390 -been busy working
64 T-34 Ghia...aka Wolfie, under construction... http://www.thesamba.com/vw/forum/viewtopic.php?t=412120
| Tram wrote: |
| "Friends are God's way of apologizing for relatives." |
| Tram wrote: |
| People keep confusing "restored" and "restroyed". |
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notchboy
Samba Member
Joined: April 27, 2002
Posts: 22462
Location: Escondido CA
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| Posted: Thu Mar 07, 2019 3:35 pm Post subject: Re: 67' Dual Carb Idle Too High |
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| Bobnotch wrote: |
| Mike Fisher wrote: |
| It's probably maladjusted rods. There is a procedure for setting them All in proper order Correctly. |
Yup, see the link I posted near the top of this thread. |
This would of been the first thing to check as the idle drop down cam under the choke needs to be able to let go or the idle stays high. 
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| t3kg wrote: |
OK, this thread is over. You win. |
Jason "notchboy" Weigel
1964 1500 S
1964 T34 S Convertible
1977 Westfalia Camper pop-top |
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Tram
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Joined: May 02, 2003
Posts: 22728
Location: Still Feelin' the Bern- Once you've felt it you can't un- feel it.
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| Posted: Thu Mar 07, 2019 11:35 pm Post subject: Re: 67' Dual Carb Idle Too High |
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| DQDan wrote: |
"Also, never use the metal gaskets for the intake manifolds commonly found in the standard "complete" gasket kits."
I'm getting ready to bolt up two 32PDSIT's on my 66 build and was going to use those metal crush washers at the base of the intakes. What do you suggest as substitutes? TIA |
'66 is single port and uses the crush washers. '67 is dual port and those are the gaskets they are talking about.
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| Bryan67 wrote: |
| Just my hands. And a little lube. No tools. |
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Tram
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Joined: May 02, 2003
Posts: 22728
Location: Still Feelin' the Bern- Once you've felt it you can't un- feel it.
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| Posted: Thu Mar 07, 2019 11:41 pm Post subject: Re: 67' Dual Carb Idle Too High |
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| notchboy wrote: |
| Bobnotch wrote: |
| Mike Fisher wrote: |
| It's probably maladjusted rods. There is a procedure for setting them All in proper order Correctly. |
Yup, see the link I posted near the top of this thread. |
This would of been the first thing to check as the idle drop down cam under the choke needs to be able to let go or the idle stays high. |
Yup. If that cam isn't dropping off the offending carb will pull. This adjustment is the bent rod that has two 7mm nuts at the threaded section at the bottom through a linkage lever off the base of the carb. Adjust the length of the rod by using the nuts so that it's the same length as the right side.
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Немає виправдання для війни! Я з Україною.
| Bryan67 wrote: |
| Just my hands. And a little lube. No tools. |
To best contact me, please use the EMAIL function in my profile |
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Jeff67sqbk
Samba Member
Joined: October 18, 2004
Posts: 35
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| Posted: Sat Apr 13, 2019 5:56 pm Post subject: Re: 67' Dual Carb Idle Too High |
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Got it!
Adjusted the rod on the carb and managed to get the idle lowered enough to balance carbs and again at higher revs.
Took it out for a quick spin around town. Feels nice to drive it again after many, too many years of not being able to!
Thanks all!
Here's a picture of the cobbled together stuff I use to hold the RPMs high for balancing carbs.
The threaded piece has a 90 degree bend to fit into the open wrench, the other piece is a bent tent peg. Wing nut for adjustment.
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