Distributor advance

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jerry havel
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Distributor advance

#1 Post by jerry havel » Fri Jul 01, 2022 5:32 pm

I have a rebuilt distributor, the VJR 4 BR 18, that doesn't return back to the minimum advance after I turn the rotor to full advance by hand. It comes back to a certain low advance point, and then I have to turn it back to its "zero" position. Not much resistance to that, but there is also a slight "ticking" when I do turn it back. So, any ideas as to the cause, and any suggestions as to how to correct the problem without disassembly?? Yes, looking for an "easy fix" here, a "magic spray"...

thanks, Jerry
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David Jones
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Re: Distributir advance

#2 Post by David Jones » Fri Jul 01, 2022 6:48 pm

You will either have to dismantle it and fix it yourself Jerry or send it off for repair. Unlikely a spray of oil will fix it.
If I had known I would live this long I would have pushed the envelope a little harder.
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Phil Planck
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Re: Distributir advance

#3 Post by Phil Planck » Fri Jul 01, 2022 7:08 pm

There is a felt pad under the rotor. Apply some light oil and let it soak in. Give it a few days and try again. Might work.
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Jim Liberty
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Re: Distributir advance

#4 Post by Jim Liberty » Fri Jul 01, 2022 7:32 pm

If not, send to John Jenkins, Carburetor Rescue. He has done dozens for me with wonderful results. ............Jim.
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Mike Wilson
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Re: Distributir advance

#5 Post by Mike Wilson » Fri Jul 01, 2022 7:37 pm

Weak springs or sticking slide plate?

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PaulLima
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Re: Distributir advance

#6 Post by PaulLima » Fri Jul 01, 2022 8:43 pm

+1 for John Jenkins. 2 perfect (of two) distributors from him

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Mike Wilson
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Re: Distributir advance

#7 Post by Mike Wilson » Fri Jul 01, 2022 8:47 pm

+2 for John.
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John Brooks
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Re: Distributir advance

#8 Post by John Brooks » Fri Jul 01, 2022 9:45 pm

Check the screw on the points and make sure it’s not touching the advance weight. Shine a light down and look for a scratch arc on the weight.
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Re: Distributir advance

#9 Post by Dick Weiss » Fri Jul 01, 2022 10:04 pm

+1 John

Jon Bunin
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Re: Distributir advance

#10 Post by Jon Bunin » Fri Jul 01, 2022 10:07 pm

jerry havel wrote:
Fri Jul 01, 2022 5:32 pm
I have a rebuilt distributor, the VJR 4 BR 18, that doesn't return back to the minimum advance after I turn the rotor to full advance by hand. It comes back to a certain low advance point, and then I have to turn it back to its "zero" position. Not much resistance to that, but there is also a slight "ticking" when I do turn it back. So, any ideas as to the cause, and any suggestions as to how to correct the problem without disassembly??
Jerry, depending on the position of the distributor cam, it can be opening the points as the advance springs reverse your twist of the rotor, and the result will be what you've described.
Twisting the rotor is not a reliable distributor test.
Jon Bunin

jay darlington
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Re: Distributor advance

#11 Post by jay darlington » Sun Jul 03, 2022 8:11 pm

can't you put it in the engine and use a timing light to test it. this would be a for sure test.
Jay D.
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Re: Distributor advance

#12 Post by Jon Bunin » Sun Jul 03, 2022 9:55 pm

jay darlington wrote:
Sun Jul 03, 2022 8:11 pm
can't you put it in the engine and use a timing light to test it. this would be a for sure test.
Jay, the best way to test distributors is on a distributor machine, or synchrograph.
In this way, they're removed from other engine issues which are often diagnosed as faulty distributors.

My dusty Allen Synchrograph serves as a shelf for other dusty items when not in use.
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Harlan Halsey
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Re: Distributor advance

#13 Post by Harlan Halsey » Sun Jul 03, 2022 10:45 pm

+1
[/quote]... the best way to test distributors is on a distributor machine.
In this way, they're removed from other engine issues which are often diagnosed as faulty distributors.
[/quote]

More common than the Allen distributer tester is the Sun version. Besides the advance curve you can see the position of each lobe (90 degrees for a 356) If a lobe is retarded you can retard the other three by polishing to achieve a match for example. I have always had access to three or four Sun machines owned by friends, but with the passage of time I'm now in the market for my own dust catcher.

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Re: Distributor advance

#14 Post by DaveErickson » Sun Jul 03, 2022 11:01 pm

Jon, I have an Allen syncrograph too, wonder which one is a newer model. Mine is interesting in that it was one of the very first programmable electronic tools. It has different logic circuits and is programmed by inserting aluminum plates that actuate switches used as logic devices. The switches tend to get dirty from lack of use, but Stabil or de-oxit keep it running. The switches on the right each have 4 or 5 layers. Makes you wonder how we got to the moon in the 60's.
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Re: Distributor advance

#15 Post by jay darlington » Sun Jul 03, 2022 11:35 pm

if one does not have access to one of these machines what would one do ?
Jay D.
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