No timing advance and one black spark plug

[billfred1]

Started running rough. All plugs except for #1 looked fine. Plug 1 was really black. Not oily black, but powdery black. Put in another plug and same thing happened right away.

Also noticed I'm getting no timing advance. Vacuum advance in dizzy is working.

Checked valves and dwell.

Any ideas?
_________________
Bill
1966 Beetle

[Teeroy]

Bad cap or wire, advance weights frozen?
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Pres. Rivercity VW Club www.rcvwclub.org
Founder Derr Wheat Panzers (DWP)
ARR #3
www.autosportsnorthwest.org

[ashman40]

Confirm the model# of your carb & distributor. Carbs with venturi vacuum for the vacuum advance port (eg. 30Pict) will not generate enough vacuum signal from the left side port for a later distributor (SVDA or DVDA) which are expecting a ported vacuum signal.

You want to match the distributor to a carb that produces the correct vacuum signal. Also, your ignition timing should be based on the distributor installed.
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AshMan40
---------------------------
'67 Beetle #1 {project car that never made it to the road }
'75 Beetle 1200LS (RHD Japan model) {junked due to frame rot}
'67 Beetle #2 {2019 project car - Wish me luck!}

[mukluk]

What are the specs of the engine we're talking about?
How are you verifying the ignition advance isn't working?
Have you checked the vacuum signal from the carb's advance port with a gauge while the engine is running?
Have you checked the spark quality at the offending plug?
Have you done a compression check to see if cylinder 1 is low?
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1960 Ragtop w/Semaphores "Inga"

[wcfvw69]

An original 66 bug would have a 113905205K installed. However, after decades, who knows which distributor is in it now.

How did you check the vacuum canister? You need to use at least a hand vacuum pump with gauge. The canister should be pumped up to say 100MM hg and then not leak down at all.

If that passes and the distributor still doesn't advance, you probably have a stuck or sticky pivot inside the distributor. It would need to come apart, cleaned and then lubricated. 99% of the SVA distributors I restore have never been apart since new and the original lubrication grease is long gone.
_________________
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[billfred1]

Thanks guys. It does have the 205k dizzy from Tasb. Mated up with a recently rebuilt 30 Pict 1 carb.

It's the stock engine with 1600 jugs. It's been running great for the past year.

How do I check spark quality? Also, regarding the timing advance, with the timing light, I no longer am seeing an advance when I gun the throttle.

When I suck on the air line going to the dizzy, I can see the points shifting.
_________________
Bill
1966 Beetle

[wcfvw69]

[mukluk]

You check spark quality at the plug similar as you would from the coil: unscrew the plug from the head, reattach the plug wire, then crank the engine over while holding the threads of the plug in contact with a good ground and observe the spark at the plug to see if it's strong or weak.

If sucking on the advance line to the distributor shows the can is working and not leaking, then you should check the vacuum signal coming from the carburetor advance port with a gauge while the engine is running -- the port may be obstructed.
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1960 Ragtop w/Semaphores "Inga"

[Eric&Barb]

If one pulls on the spark plug cable to pull the socket that plugs over the spark plug, and if the spark plug cables are built like the original VW ones. Then the rubber insulation of the cable could have stretched and the copper strand wires do not stretch. So the copper wire strands are no longer in contact with the brass screw/stud of the socket. Unscrew the socket from that cable, trim off the insulation till at least 1/8" 3mm of the copper strands sticking out. Bend the strands flat to the end of the insulation, and rescrew back on the socket.
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In Stereo, Where Available!

[billfred1]

[billfred1]

[wcfvw69]

My bet is the vacuum canister is failing or failed. You'd need to "T" in a vacuum gauge on that vacuum line going to the vacuum canister. That carb will probably put out a max of around 110 mm HG of vacuum.

If you need a good, used and correct vacuum canister for the 205K, I have some for a fair price. PM me if needed.
_________________
Contact me at [email protected]
Follow me on instagram @sparxwerksllc

Decades of VW and VW parts restoration experience.
The Samba member since 2004.

**Now rebuilding throttle bodies for VW's and Porsche's**
**Restored German Bosch distributors for sale or I can restore yours**
**Restored German Pierburg fuel pumps for sale or I can restore yours**
**Restored Porsche fuel pumps or I can restore yours**
**Restored Porsche distributors or I can restore yours**

[mukluk]

[billfred1]

I'm starting to think I might have carb issues. When I advance the plate with my fingers and then cover the hole on the canister, the plate stays in place, it doesn't move back like it would if there was a leak.

Now I'm seeing all 4 plugs are black. Just in the time I've been running it in the garage, the other ones are now black. Checked compression on one cylinder. I'm getting about 115 psi. I just put new rings in about 10 months ago.
Also, I'm getting a good spark.
_________________
Bill
1966 Beetle

[billfred1]

I got a vacuum gauge. Going to try to do some testing this weekend.

Could the lack of timing advance lead to the black (carbon) plugs?
_________________
Bill
1966 Beetle

[mukluk]

[billfred1]

Vacuum gauge is showing a steady 5 in Hg regardless of the RPM.

I also notice when I disconnect the line from the carb to the dizzy it nearly dies.
_________________
Bill
1966 Beetle

[mukluk]

[wcfvw69]

Bill- do you have an ultrasonic parts cleaner? I had some issues one time with a German Solex 34-3. It had a clogged idle passage/port deep inside it. Dipping it in carb cleaner didn't do anything. I washed it out and sprayed all the passaged out with carb cleaner. Still clogged. This carb body was spotless inside and out I thought.

I finally dunked it in the hot/soapy water of an ultrasonic parts cleaner that was 140°. I let it run for 30 minutes. The clean water was black when I pulled what I thought was a clean carb body out of the water. The passages were clear after that.
_________________
Contact me at [email protected]
Follow me on instagram @sparxwerksllc

Decades of VW and VW parts restoration experience.
The Samba member since 2004.

**Now rebuilding throttle bodies for VW's and Porsche's**
**Restored German Bosch distributors for sale or I can restore yours**
**Restored German Pierburg fuel pumps for sale or I can restore yours**
**Restored Porsche fuel pumps or I can restore yours**
**Restored Porsche distributors or I can restore yours**

[billfred1]

I might be able to get my hands on an ultrasound cleaner. Any recommendations on trying to clean it out if I can’t?
_________________
Bill
1966 Beetle