Distributor advance

356 Porsche-related discussions and questions.
Message
Author
Jerry Havel
356 Fan
Posts: 86
Joined: Sat Aug 02, 2008 11:43 am
Location: New jersey

Distributor advance

#1 Post by Jerry Havel »

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
jerry havel

User avatar
David Jones
Classifieds Moderator
Posts: 7324
Joined: Tue Mar 25, 2008 6:32 pm
Tag: I wish I knew as much as I think I know.
Location: Kentucky

Re: Distributir advance

#2 Post by David Jones »

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.
Cymru am byth
David Jones #9715

User avatar
Phil Planck
356 Fan
Posts: 2030
Joined: Wed Mar 26, 2008 7:21 pm
Location: NE Michigan, lower penn.

Re: Distributir advance

#3 Post by Phil Planck »

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.
Phil Planck

User avatar
Jim Liberty
356 Registry Member
Posts: 4313
Joined: Tue May 06, 2008 3:47 pm
Tag: Jim
Location: Orange Co., CA
Contact:

Re: Distributir advance

#4 Post by Jim Liberty »

If not, send to John Jenkins, Carburetor Rescue. He has done dozens for me with wonderful results. ............Jim.
Jim Liberty

User avatar
Mike Wilson
Classifieds Monitor
Posts: 11492
Joined: Tue Apr 15, 2008 4:37 pm
Location: SW Los Angeles

Re: Distributir advance

#5 Post by Mike Wilson »

Weak springs or sticking slide plate?

Mike
Mike Wilson
Lomita, CA
'63 B coupe

User avatar
Paul Lima
356 Fan
Posts: 507
Joined: Fri Jan 10, 2014 2:02 pm
Location: Gardnerville, NV

Re: Distributir advance

#6 Post by Paul Lima »

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

User avatar
Mike Wilson
Classifieds Monitor
Posts: 11492
Joined: Tue Apr 15, 2008 4:37 pm
Location: SW Los Angeles

Re: Distributir advance

#7 Post by Mike Wilson »

+2 for John.
Mike Wilson
Lomita, CA
'63 B coupe

User avatar
John Brooks
356 Fan
Posts: 2146
Joined: Tue Jul 08, 2008 11:50 am
Location: Whidbey Island WA.
Contact:

Re: Distributir advance

#8 Post by John Brooks »

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.
John Brooks

62 Roadster
66 912
84 Cab
getting pushed around in porsches since 1965

Dick Weiss
356 Fan
Posts: 4183
Joined: Sun Apr 20, 2008 12:54 am

Re: Distributir advance

#9 Post by Dick Weiss »

+1 John

Jon Bunin
356 Fan
Posts: 1800
Joined: Thu Oct 15, 2009 11:06 pm
Location: Vista, CA

Re: Distributir advance

#10 Post by Jon Bunin »

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
356 Fan
Posts: 1347
Joined: Fri Dec 12, 2008 1:15 pm
Location: coos bay oregon

Re: Distributor advance

#11 Post by Jay Darlington »

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.
jay darlington

Jon Bunin
356 Fan
Posts: 1800
Joined: Thu Oct 15, 2009 11:06 pm
Location: Vista, CA

Re: Distributor advance

#12 Post by Jon Bunin »

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.
Attachments
DSCN0227.JPG
Jon Bunin

User avatar
Harlan Halsey
356 Fan
Posts: 2340
Joined: Fri Mar 02, 2012 2:05 pm
Location: No Cal SF Peninsula

Re: Distributor advance

#13 Post by Harlan Halsey »

+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.

Dave Erickson
356 Fan
Posts: 2191
Joined: Sat Oct 26, 2013 9:34 pm
Location: Monterey, CA

Re: Distributor advance

#14 Post by Dave Erickson »

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.
IMG_0544.jpeg
IMG_0545.jpeg
IMG_0546.jpeg

Jay Darlington
356 Fan
Posts: 1347
Joined: Fri Dec 12, 2008 1:15 pm
Location: coos bay oregon

Re: Distributor advance

#15 Post by Jay Darlington »

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

Post Reply