Another Weber DCOE Post

[Inka’d02]

51 minutes ago, uai said:

What you describe is the symptom if advance starts before 1000 RPM.

Advance should be static 10° and not variable before 1000 RPM.

I do this by preloading the first spring in the dizzy

 So what you are saying is IF the advance is 10 at 1000RPM and when the idle drops to 600 it should still be at 10 degrees, correct? If it is not here is a couple of questions:

1. How would I go about pre-loading the first spring in a way that is reversible if it does not improve things?

2. Which spring is the first one? One extension spring in my distributor is under tension and one is loose (slightly longer) when the car is off.  

 

Edited July 15, 2020 by Inka’d02

['76mintgrün'02]

Thanks for posting the video that provided a glimpse of the distributor.  At least now we know which type of advance mechanism we are dealing with here.  It is a model #002, correct?  (please?)

 

Here is a photo of my cap, when I had a PerTronix installed in my 002 distributor.  It shows the symptom I described above.

 

That is not going to cause your issue, but if you have the problem of the rotor not being able to fully seat, it might be rubbing hard on the cap.  Could you please post a photo of the top of your rotor?

 

 

 

1 hour ago, Inka’d02 said:

2. Which spring is the first one? One extension spring in my distributor is under tension and one is loose (slightly longer) when the car is off.  

 

The one that has tension on it is the first one, or the "idle spring".  The other one is the "looped spring" and it does not come into play until the center post pin reaches the end of the loop.

 

1 hour ago, Inka’d02 said:

1. How would I go about pre-loading the first spring in a way that is reversible if it does not improve things?

 

You can remove the little oval cover in the side of the distributor and reach through that hole to bend the tab, using a homemade tool similar to the ones Uai showed on page one of this thread.  Here is a photo of mine in use on the looped spring tab

 

The photo below is actually bending the stop tab for the weights, but it's the same idea.  You'll be pushing down on the tool, to bend the top of the tab out, putting more tension on the spring.

 

 

In this photo you can see that the tool needs to be shaped in order to give clearance when bending.

 

 

As for it being reversible, you'll need to measure in from the edge of the hole, to see where the spring post is now; so that you can bend it back.

 

I made this tool for bending the stop tabs, so I could be more accurate and sure that they were both the same.  

(mostly sharing for the fun of it -- aka, showing off, I suppose)

 

 

 

 

You could poke a bamboo skewer (or something) through the hole and mark the edge of the body on it with a knife, or a sharp pencil and use that as a reference for where it is now.

 

Have you put your curve on paper yet?  

 

Tom

 

Edited July 15, 2020 by '76mintgrün'02
added one more photo

[Inka’d02]

52 minutes ago, '76mintgrün'02 said:

Thanks for posting the video that provided a glimpse of the distributor.  At least now we know which type of advance mechanism we are dealing with here.  It is a model #002, correct?  (please?)

 

Here is a photo of my cap, when I had a PerTronix installed in my 002 distributor.  It shows the symptom I described above.

 

That is not going to cause your issue, but if you have the problem of the rotor not being able to fully seat, it might be rubbing hard on the cap.  Could you please post a photo of the top of your rotor?

 

 

 

 

The one that has tension on it is the first one, or the "idle spring".  The other one is the "looped spring" and it does not come into play until the center post pin reaches the end of the loop.

 

 

You can remove the little oval cover in the side of the distributor and reach through that hole to bend the tab, using a homemade tool similar to the ones Uai showed on page one of this thread.  Here is a photo of mine in use on the looped spring tab

 

The photo below is actually bending the stop tab for the weights, but it's the same idea.  You'll be pushing down on the tool, to bend the top of the tab out, putting more tension on the spring.

 

 

In this photo you can see that the tool needs to be shaped in order to give clearance when bending.

 

 

As for it being reversible, you'll need to measure in from the edge of the hole, to see where the spring post is now; so that you can bend it back.

 

I made this tool for bending the stop tabs, so I could be more accurate and sure that they were both the same.  

(mostly sharing for the fun of it -- aka, showing off, I suppose)

 

 

 

 

You could poke a bamboo skewer (or something) through the hole and mark the edge of the body on it with a knife, or a sharp pencil and use that as a reference for where it is now.

 

Have you put your curve on paper yet?  

 

Tom

 

Thank you Tom, I will get that photo tonight. Just to confrim, the advance should not drop any lower than 10 degrees even if the RPM drops lower then 1000rpm?

['76mintgrün'02]

Correct.  We're trying to determine when the advance actually starts to move.  You don't want more advance left hanging below your target idle speed.

 

I'd suggest actually plotting the curve, as it sits now, so you can share that information with us and use it as a reference if you make changes to the distributor. 

 

Note when it starts to move and then plot every 200 rpm or so until it stops and note where it is and when that happens. 

 

(see Preyupy's post on page one).

 

Bending that idle spring tab will also make the advance come in a little slower, which is fine.

 

(Bending the loop spring tab will flatten the upper part of the curve, or at least change when it starts to flatten.  Changing that really helped my car and eliminated the pinging at 2-3k rpm.)  

 

Tom

 

 

 

['76mintgrün'02]

I just went up and spun the #164 that is sitting in the sun machine.  At low rpm I can grab the center post between my thumb and finger and pinch while I watch two degrees of advance come into play.  Those results will vary, based on spring tension and such, but it is not hard at all to affect the early part of the curve.  (see Byron's post above about that affecting the engine rpm)

 

It occurred to me that the friction produced by a rotor not seating would not only exist at the top of the rotor, but also at the bottom of the center post, where it meets the shaft.  There is sight height-gap built into the post to allow it to move freely (if lubed) and pinching it down tight would inhibit it from moving (as freely) .

 

The thing will advance, because the weights pull nice and hard at higher rpms, but they springs are weak when it comes to pulling it back.  Especially at the bottom end.

 

Tom

[Inka’d02]

7 hours ago, Inka’d02 said:

Thank you Tom, I will get that photo tonight. Just to confrim, the advance should not drop any lower than 10 degrees even if the RPM drops lower then 1000rpm?

 

['76mintgrün'02]

Thank you for the photo of your nice clean cap.  I put the one with the arc marks in to show that 'other' problem, but your marks look nicely centered.  That's good.

 

You can see that the arc marks are up near the top of the copper bits.  That shows that the rotor is riding high on the post.  Maybe not unusually high though.  The ones that I have seen that rubbed usually have some dust and stuff from the abrasion.

 

I am curious what the top of the rotor looks like. 

 

Usually you can tell if it has been rubbing on the bottom of the cap for a while.  There'll be a ring there.

 

 

[Inka’d02]

1 hour ago, '76mintgrün'02 said:

Thank you for the photo of your nice clean cap.  I put the one with the arc marks in to show that 'other' problem, but your marks look nicely centered.  That's good.

 

You can see that the arc marks are up near the top of the copper bits.  That shows that the rotor is riding high on the post.  Maybe not unusually high though.  The ones that I have seen that rubbed usually have some dust and stuff from the abrasion.

 

I am curious what the top of the rotor looks like. 

 

Usually you can tell if it has been rubbing on the bottom of the cap for a while.  There'll be a ring there.

 

 

I think we got it! Put the rotor in my milling machine and to 1 mm off. Also I checked the timing, consistently coming down to 10 degrees and no lower. I did tweak the timing alittle as well. 

 

Now I just need to sort out that crackle pop on deceleration sometimes. NO I DO NOT HAVE ANY EXHAUST LEAKS!.

 

I will keep you posted on how it drives tomorrow.

 

Thanks again for the help everyone!

[Chris_B]

12 hours ago, Inka’d02 said:

 

At the end of the day I just need the car to back to idle faster, not pause at 1500 and take time to drop. And second I need it to not continue to fall after it hits 1000/1050 RPM.

 

 

Have you tried increasing the idle speed when the idle falls to below 1K RPMs, to keep it at 1K? I am not sure yet why you have the lazy idle, but as the RPMs drop your idle mixture will be changing commensurately, which may be the reason that the RPMs keep dropping- a vicious cycle. Do you have a wide band 02 sensor/AFM (sorry, i looked through this thread and didn't see anything about that. It would be interesting to know what his happening with the mixture when the idle speed falls. 

[Inka’d02]

12 minutes ago, Chris_B said:

Have you tried increasing the idle speed when the idle falls to below 1K RPMs, to keep it at 1K? I am not sure yet why you have the lazy idle, but as the RPMs drop your idle mixture will be changing commensurately, which may be the reason that the RPMs keep dropping- a vicious cycle. Do you have a wide band 02 sensor/AFM (sorry, i looked through this thread and didn't see anything about that. It would be interesting to know what his happening with the mixture when the idle speed falls. 

See last post, looks to be solved(fingers crossed)

['76mintgrün'02]

Just now, Inka’d02 said:

See last post, looks to be improved  (fingers crossed)

 

FTFY ^

 

I'll bet it is still too tall.

 

26 minutes ago, Inka’d02 said:

Put the rotor in my milling machine and to 1 mm off.

 

1mm is less than half of the 1/10 of an inch I suggested above.

 

I would take another .060" off of the bottom.  (1.5 mm, if you'd prefer)

 

 

 

I was discussing binding center posts with Toby earlier today and he gave this insight, 

 

" it'll lag on the retard coming back down, too. <pop> <pop> <pdddoppp> "

 

Maybe sort of kind of like your video, perhaps?  

 

 

 

41 minutes ago, Inka’d02 said:

Also I checked the timing, consistently coming down to 10 degrees and no lower.

 

I would try lowering the idle rpm to 800 and see if it still has 10 degrees of advance, just to be sure that's the bottom of the curve.

What rpm does the advance start to move towards 11 degrees?

 

 

42 minutes ago, Inka’d02 said:

I did tweak the timing alittle as well. 

 

I would plot the advance curve and share the information here.

 

But, that's just me.

Maybe you're done!

 

Tom

 

[antares242]

On 7/2/2020 at 8:27 AM, '76mintgrün'02 said:

 

It sounds like you have a late style distributor uai.  Thanks for sharing your curve/process.

 

The Ti distributors were the earlier style, with two small symmetrical springs that rub alongside lobes on the center post and they stretch as it rotates.  The springs get a flat spot worn on the side that is up against the lobe, which makes them weaker over time.

 

There is an adjustment built into the early distributors that allows you to add tension to the springs by rotating the outer attachment pins, which may encourage it to return a bit better; while also slowing the start of the curve.  Unfortunately, you have to drill the pin and disassemble the distributor to get at the adjustment.  Fortunately, that is fun to do and not very difficult.

 

In both early and late distributors, you need to make sure the center post can move freely on the shaft.  Try grabbing the post and rotating it by hand and you'll feel the advance mechanism moving.  It should feel smooth and want to snap back to "zero".  I am guessing yours might be binding there.

 

You could try digging out the felt plug in the post and putting some oil down the center.  That is considered basic maintenance, but the instructions usually say to put a couple drips on top of the felt plug.  Pull the plug and put the oil underneath it, then put the plug back.

 

The early style distributors slide on a pad under the weights to prevent metal to metal contact with the plate below and the nubs on the bottom of the weights will eventually rub through it.  The pad is brittle and often breaks into pieces that can inhibit the weights' movement.  Those pads are available separately, (if you do decide to dig into it).

 

I am more than happy to type about this stuff, but you've probably already ordered a 123 by now.   

 

Tom

 

 

Hello Tom, I’m currently rebuilding my distributor and as you said, the pad came out in pieces. Where can I source one online? Thanks!

['76mintgrün'02]

8 hours ago, antares242 said:

Hello Tom, I’m currently rebuilding my distributor and as you said, the pad came out in pieces. Where can I source one online?

 

Stoddard sells them. 

 

https://www.stoddard.com/nla60210201-61660210201-nla.html

 

They also have some of the small springs that fit the early style distributors, but I don't know how close they'll be to the ones inside your distributor.  They might be worth a try though. 

 

https://www.stoddard.com/nla60265004-61660265004-nla.html

 

The springs get a flat spot worn on the side, where they rub up against the lobes on the center post.

 

Here is a link to a thread in which I took a few distributors apart.  This was the first early-style one I looked into.

 

 

Have fun!

 

Tom