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Unread 05-08-2012, 02:10 PM   #16
kovic
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Hey I made the pics bigger. I added one of my fuel filter that is before the regulator, it is a 1 in 2 out, one line goes to regulator then carb, other works its way down and connects to a steel line that im guessing makes its way to the gas tank, but it should go to canister?

Yes you do see another fuel filter, its before my electric fuel pump, I dont have a mechanical one anymore, and I was told I needed a filter before the electric one, should I remove it?

So my plumbing looks good, how about my vacuum lines, the pics show how it always was, but when I hook the vacuum advance up it pulls the actuator arm, and most the pics I see on this site shows the advance hooked to the S port...

And I guess i can remove the reg.

And recommendations.

thanks

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Unread 05-08-2012, 05:47 PM   #17
newtome
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It will run smooth if you throw away the weber and put on howell efi
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Unread 05-08-2012, 06:06 PM   #18
keith460
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For one thing, as Matt1981CJ7 has suggested, I would eliminate the FPR as they are not necessary and cause more problems then they are worth. I would even go as far as installing a factory type mechanical fuel pump to replace the electric one that you said is installed. As long as you can use the factory type 1 in- 2 out fuel filter that regulates and meters the fuel entering the carb, their is no need to have the extra pieces in the fuel supply plumbing that may malfunction and make it harder to diagnose fuel problems with the Weber carb. Getting back to basic is one of the key elements in establishing good idle and fuel flow within the Weber carb.

Vacuum lines can be setup a couple of ways and photos below give an example when using the the EGR, PCV, CTO, Charcoal Canister and ported vacuum for the the Distributor. Ported or Manifold vacuum is a matter of choice for the Distributor as either way will work and results vary slightly. I currently have my Weber 32/36 on ported vacuum and intial timing is set at 10-12 BTDC. Ran it with manifold vacuum before and set my timing to 8 BTDC, didn't notice much of a change but that may be due to the fact that the Distributor is an original computer controlled unit and lacks the proper centrifugal weights and springs as pre 1981 models have.







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Unread 05-08-2012, 06:47 PM   #19
kovic
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Thanks Keith460 for the pictures, much needed. I will try to set my vacuum lines up as you did. I will also get rid of the electric pump, and replace it with a mechanical one, remove one of the fuel filters, and remove the FPR.

Now on your setup, C on your canister, is that needed? Also, my CTO is connected to my S port and EGR, what should I do with the CTO nipple that went to the S port once I have the vacuum advance go there?

Also, When the advance is hooked to the manifold it changes my idle, the little arm that moves on the distributor get pulled as soon as the manifold vacuum is attached, and it doesnt get pulled when the S port is attached, is that normal?

If the idle screw can only be in 1 1/2 turns, how do I raise my idle to 700-900?

Thanks
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Unread 05-08-2012, 07:03 PM   #20
86cj74.2L
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Quote:
Originally Posted by "
I currently have my Weber 32/36 on ported vacuum and intial timing is set at 10-12 BTDC. Ran it with manifold vacuum before and set my timing to 8 BTDC, didn't notice much of a change but that may be due to the fact that the Distributor is an original computer controlled unit and lacks the proper centrifugal weights and springs as pre 1981 models have.
My last project was replacing the 6.5r computer dizzy with a 18r/23r.

I went junking and found a reman dizzy with the 18r advance head on the 3rd FSJ I came to.

Installed it and what a difference. One thing I never expected was now that it has more timing at higher RPM's the engine doesn't sound near as busy above 45mph. It's actually a lot more quiet.
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Unread 05-08-2012, 07:13 PM   #21
Matt1981CJ7
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Quote:
Originally Posted by kovic View Post
Also, When the advance is hooked to the manifold it changes my idle, the little arm that moves on the distributor get pulled as soon as the manifold vacuum is attached, and it doesnt get pulled when the S port is attached, is that normal?

Thanks
That's the way manifold vacuum works. It adds advance at idle, and at no load (coasting) situations. Many of us prefer this over s-ported vacuum because is improves cold starts and low-end performance. It helps to modify the centrifugal advance when using manifold vac. But, that's a discussion for another time.

Good choice on loosing the electric pump and extra filter.

Matt
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Unread 05-08-2012, 07:19 PM   #22
keith460
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Quote:
Originally Posted by kovic View Post
Now on your setup, C on your canister, is that needed? Also, my CTO is connected to my S port and EGR, what should I do with the CTO nipple that went to the S port once I have the vacuum advance go there?

Also, When the advance is hooked to the manifold it changes my idle, the little arm that moves on the distributor get pulled as soon as the manifold vacuum is attached, and it doesnt get pulled when the S port is attached, is that normal?

If the idle screw can only be in 1 1/2 turns, how do I raise my idle to 700-900?

Thanks
Either port on the Weber shown is a S port but Weber list the one I show going to the CTO and Canister purge as "additional". I just used the S port by itself for the distributor advance. The canister needs the ported vacuum in order to pull vapors while the engine is under load or accelerating. There is no vacuum at manifold vacuum source unless the engine is at idle or decelerating. So yes, "C" is needed. You want the charcoal canister to be pulling out the vapors and fumes from the carb bowl and gas tank at all times when you are driving or sitting at a light idling.

When the distributor is hooked up to "full" manifold vacuum your distributor "will" advance because vacuum is present while idling. Hooked up to the "S" port, their will be no vacuum present at idle until the throttle plate opens and exposes the port to allow vacuum to be pulled. This is where you need to pay attention to your speed screw settings so as not to expose the "S" port while adjusting for lean best idle. Use a vacuum gauge hooked up to the "S" port to acknowledge 0 vacuum at that port.

Is there a reason to raise your idle to 700-900 rpm? I idle right about 500-600 rpm using ported vacuum for the distributor. 1200 rpm on cold start-up with the choke closed.
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Unread 05-08-2012, 09:23 PM   #23
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Ok, so manifold vac is preferred, it seems S port left me with a better idle... but maybe I have some other issue

And right now my canister has 2 of the 4 ports plugged, the other to go to the gas tank, and the float bowl vent, so that is not good, you are saying there needs to be a vacuum source going there?

And I thought 7-900 was preferred for idle, and mine barely wants to live at 500 rpms.... How do you have 1200 rpm at cold start, is that something to do with the speed screw?

And right now I have the idle screw in 1 1/2 turns, with zero vacuum at the S port

Tomorrow I will clean up my fuel lines, remove the extra fuel filter, the electric pump (replaced with the mechanical), and the FPR. I will let you guys know how that goes, and then I will focus on the vacuum set up also.

Thank you all for your help! I really appreciate it
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Unread 05-08-2012, 09:43 PM   #24
keith460
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Originally Posted by kovic View Post
And I thought 7-900 was preferred for idle, and mine barely wants to live at 500 rpms.... How do you have 1200 rpm at cold start, is that something to do with the speed screw?
1200 rpm is the fast idle setting when the choke is closed. Its another screw adjustment that is separate from the idle screw.
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Unread 05-09-2012, 01:00 AM   #25
mcmud
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Quote:
Originally Posted by keith460 View Post
Either port on the Weber shown is a S port but Weber list the one I show going to the CTO and Canister purge as "additional".
Actually the DGxV has both an "S" and "E" ported vacuum... and the labeling of either depends on which document you view. There is also one other, a Venturi port vacuum nipple available at the linkage side of the body.

The "S" and "E" are at different heights, the "S" being lower in the bore than the "E", will come in sooner and then with the "E" being positioned more toward the throttle rod than the "S" it will provide a much smoother increase or decrease in signal strength than the "S", more linear to the throttle position.

With the Venturi port being much higher than the bore ports its signal arrives at or very near WOT.

Quote:
There is no vacuum at manifold vacuum source unless the engine is at idle or decelerating. So yes, "C" is needed.
There certainly is. A manifold vacuum signal is present at all times other than the short lived blip to 0" at the very onset of hammering the pedal. In fact overall its signal is very near, at times identical to the Weber DGxV "S" port vacuum. Then they differ to the extreme at idle.... if the throttle plate is set as it should be... below the "S" port.

Quote:
You want the charcoal canister to be pulling out the vapors and fumes from the carb bowl and gas tank at all times when you are driving or sitting at a light idling.
If this ^ were so why would it be recommended to use a ported signal. At idle there should be no triggering vacuum signal to the canister, no purge.

Quote:
When the distributor is hooked up to "full" manifold vacuum your distributor "will" advance because vacuum is present while idling. Hooked up to the "S" port, their will be no vacuum present at idle until the throttle plate opens and exposes the port to allow vacuum to be pulled. This is where you need to pay attention to your speed screw settings so as not to expose the "S" port while adjusting for lean best idle. Use a vacuum gauge hooked up to the "S" port to acknowledge 0 vacuum at that port.

Is there a reason to raise your idle to 700-900 rpm? I idle right about 500-600 rpm using ported vacuum for the distributor. 1200 rpm on cold start-up with the choke closed.
Quote:
Originally Posted by kovic View Post
Ok, so manifold vac is preferred, it seems S port left me with a better idle... but maybe I have some other issue
You may well have a better idle quality using the "S" port. Depends on the idle mixture. A leaner mixture will require more timing advance than a richer or a stoich mix in order to produce the higher manifold vacuum, a smoother idle.

Quote:
And I thought 7-900 was preferred for idle, and mine barely wants to live at 500 rpms....
An idle speed nearer to 550 may be the ultimate goal and I believe it is obtainable once you better match the mixture to spark timing. Anything above that (which is entirely possible) will result in a waste...IMHO.

First you'll lose the economy that the DGxV was designed to deliver, then the advantage of having a ported vacuum signal is out the window due to uncovering the "S" port.


Quote:
And right now I have the idle screw in 1 1/2 turns, with zero vacuum at the S port

Tomorrow I will clean up my fuel lines, remove the extra fuel filter, the electric pump (replaced with the mechanical), and the FPR. I will let you guys know how that goes, and then I will focus on the vacuum set up also.

Thank you all for your help! I really appreciate it
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Unread 05-09-2012, 06:33 AM   #26
Matt1981CJ7
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Quote:
Originally Posted by 86cj74.2L View Post
My last project was replacing the 6.5r computer dizzy with a 18r/23r.

I went junking and found a reman dizzy with the 18r advance head on the 3rd FSJ I came to.

Installed it and what a difference. One thing I never expected was now that it has more timing at higher RPM's the engine doesn't sound near as busy above 45mph. It's actually a lot more quiet.
86,

Did you flip the advance head to the 23r side? Just wondering.

My old Motorcraft had the 13r/18r slots. I flipped it to the 18r side, then lightened up the springs considerably.

Here's the before and after advance curves. I'm still amazed at what a difference waking up that old dizzy made.

Matt
advance-curve-1.png   advance-curve-5.jpg  
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Unread 05-09-2012, 06:39 AM   #27
86cj74.2L
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You know I'm only assuming that 23r was the other side. I left the 18r up for now.......
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Unread 05-09-2012, 09:35 AM   #28
kovic
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Thanks mcmud, should I open up the 'E' port and have that go to the canister? Like I had said before 2 of the ports are plugged, with the other going to the gas tank, and float bowl vent. Is that correct?

thanks
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Unread 05-09-2012, 09:49 AM   #29
Matt1981CJ7
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This may help.
vacuumlayout.jpg  
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Unread 05-09-2012, 11:57 AM   #30
kovic
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Mine doesn't have the stock aircleaner, and my CTO only has two ports.
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