Author |
Message |
CotyWeaver Samba Member
Joined: September 16, 2018 Posts: 15 Location: Tennessee
|
Posted: Fri Sep 21, 2018 7:27 pm Post subject: Re: 72 Super having some trouble. Can anyone help? Thanks! |
|
|
Just got it to idle for a minute, the left heat riser was warm, the right side was cold... |
|
Back to top |
|
|
sb001 Samba Member
Joined: May 19, 2011 Posts: 10399 Location: NW Arkansas
|
Posted: Fri Sep 21, 2018 8:48 pm Post subject: Re: 72 Super having some trouble. Can anyone help? Thanks! |
|
|
CotyWeaver wrote: |
Just got it to idle for a minute, the left heat riser was warm, the right side was cold... |
Randy in Maine wrote: |
The heat risers supply exhaust system heat to the bottom side of the carb to keep the air:fuel mixture in suspension as it travels down the long intake runners to the heads.
Using a gloved hand feel those heat risers as the car idles in your driveway. It should get quite toasty warm in about 2-5 minutes.
Sometimes after market exhaust systems have to be "drilled out" to get the air air to flow from the left side exhaust to the carb and then out the right side exhaust.
When there is no heat provided or the heat risers get plugged up with carbon, the venturi effect will cause frost to ice to form on the bottom side of the carb. More humidity in the air makes it even worse. The car will run crappy because it is trying to burn liquid fuel not an air:fuel mixture.
If you have dual carbs, you won't need the risers as the carb sits right on top of the head. |
THIS!!!!! ^^^^
To the OP-- if your carb is getting cold (as you say it is), and you are getting rich gas-smelling spark plugs, AND you say that one heat riser side is hot but the other side is cold (not even warm to the touch right?) my vote is with Randy that your heat risers are clogged up. The fuel is not atomizing properly in the venturi on its way to the combustion chambers. I cannot really tell from your photo but it appears you have some sort of aftermarket header exhaust on the car, which makes me wonder if your heat riser flanges on the exhaust ports are even drilled out (these would have been used with dual carbs which as Randy mentioned sit above the heads so no heat risers are necessary.)
Please do a quick read here, this is a good explanation of how the heat risers work and how the can compromise the fuel delivery if clogged or the flanges not drilled out (which can lead to the exact kind of stuttering/ jerking you are experiencing):
http://www.vw-resource.com/heat_risers.html
On a side note a couple of other folks on here have asked what kind of carburetor that is, I am interested to find out as well!
Hope this helps and wasn't so incredibly "OBVIOUS" that someone else feels the need to come on here and muck up your thread. _________________ I'm the humblest guy on this board.
1969 autostick sedan, family owned since new
1600 SP engine
Solex 30 PICT 3 carburetor
Bosch 113905205AE autostick distributor |
|
Back to top |
|
|
VW_Jimbo Samba Member
Joined: May 22, 2016 Posts: 9880 Location: Huntington Beach, CA
|
Posted: Sun Sep 23, 2018 12:00 am Post subject: Re: 72 Super having some trouble. Can anyone help? Thanks! |
|
|
What did the spark look like? Poor spark can simulate symptoms of flooding or runner ng rich, bad idle quality and many other symptoms. I, myself, have chased similiar symptoms the wrong direction. Learned to check spark, valves and compression, before I ever think a carb has an issue.
Check your spark. Either rule as good and move on to the next step, or fix what is deficient. _________________ Jimbo
There is never enough time to do it right the first time, but all the time necessary the second time!
TDCTDI wrote: |
Basically, a whole bunch of fuckery to achieve a look. |
67rustavenger wrote: |
GFY's Xevin and VW_Jimbo! |
|
|
Back to top |
|
|
ArnoudH Samba Member
Joined: December 30, 2008 Posts: 162 Location: The Lowlands
|
|
Back to top |
|
|
sb001 Samba Member
Joined: May 19, 2011 Posts: 10399 Location: NW Arkansas
|
Posted: Sun Sep 23, 2018 10:29 am Post subject: Re: 72 Super having some trouble. Can anyone help? Thanks! |
|
|
Great find! Perfect explanation of what's going on with your progrssive carb and heat risers. _________________ I'm the humblest guy on this board.
1969 autostick sedan, family owned since new
1600 SP engine
Solex 30 PICT 3 carburetor
Bosch 113905205AE autostick distributor |
|
Back to top |
|
|
CotyWeaver Samba Member
Joined: September 16, 2018 Posts: 15 Location: Tennessee
|
Posted: Wed Sep 26, 2018 12:53 pm Post subject: Re: 72 Super having some trouble. Can anyone help? Thanks! |
|
|
Update. I got a chance to clean out the heat risers. Once I put everything back together it started right up. It still idles rough but it will at least idle for a minute and smoothly for the most part.
I also lost the e-ring that attaches the choke to the carb. The instructions said not to lose it, but I'm a rebel. I think I bought one that might fit and will put it on tonight. Since the choke wasn't working 100% because of this, I'm hoping this is why it was rough idling last night and might be the piece to the puzzle. |
|
Back to top |
|
|
sb001 Samba Member
Joined: May 19, 2011 Posts: 10399 Location: NW Arkansas
|
Posted: Wed Sep 26, 2018 1:33 pm Post subject: Re: 72 Super having some trouble. Can anyone help? Thanks! |
|
|
So both sides of the heat riser get nice and toasty now with the engine running? Were the heat risers severely clogged up? How did you clean them out?
When the heat riser was off did you happen to check the flanges it mounts to to make sure those are drilled through to the exhaust?
The rest of your issue is most likely that ginormous progressive carb, yes. _________________ I'm the humblest guy on this board.
1969 autostick sedan, family owned since new
1600 SP engine
Solex 30 PICT 3 carburetor
Bosch 113905205AE autostick distributor |
|
Back to top |
|
|
CotyWeaver Samba Member
Joined: September 16, 2018 Posts: 15 Location: Tennessee
|
Posted: Fri Nov 16, 2018 5:00 pm Post subject: Re: 72 Super having some trouble. Can anyone help? Thanks! |
|
|
Alright, update, in case anyone was wondering.
I got tired of fooling with it so I took it to a mechanic. He had it a month (though I don't think he spent much time on it) and couldn't figure it out. Changed the coil and maybe the points. I took it to another mechanic that assured me he could fix it, no problem. A week later he tells me to pick it up, it was just the condenser. The next day, the problem came back. Won't idle long, roughly when it does, and shuts down giving it any gas at all.
I was told that there was only supposed to be 8.75 to 9 volts coming out of the coil. I had time to check it, it was 11 volts when it was off and all over the place running. A friend told me I needed a ballast resistor to fix that because it didn't sound like the coil had an internal one...
I ordered the parts and should have them tomorrow. I'll update everyone as it goes... |
|
Back to top |
|
|
CotyWeaver Samba Member
Joined: September 16, 2018 Posts: 15 Location: Tennessee
|
Posted: Fri Dec 28, 2018 12:10 pm Post subject: Re: 72 Super having some trouble. Can anyone help? Thanks! |
|
|
I replaced the condenser again and it ran fine for a week then started acting up again. I replaced the distributor with an electric one to get by the condenser and points and it idles fine, but jerks and misses under any load. |
|
Back to top |
|
|
VW_Jimbo Samba Member
Joined: May 22, 2016 Posts: 9880 Location: Huntington Beach, CA
|
Posted: Fri Dec 28, 2018 12:37 pm Post subject: Re: 72 Super having some trouble. Can anyone help? Thanks! |
|
|
Why not take it back to the last repair shop you took it to? _________________ Jimbo
There is never enough time to do it right the first time, but all the time necessary the second time!
TDCTDI wrote: |
Basically, a whole bunch of fuckery to achieve a look. |
67rustavenger wrote: |
GFY's Xevin and VW_Jimbo! |
|
|
Back to top |
|
|
CotyWeaver Samba Member
Joined: September 16, 2018 Posts: 15 Location: Tennessee
|
Posted: Tue Jan 08, 2019 6:47 am Post subject: Re: 72 Super having some trouble. Can anyone help? Thanks! |
|
|
I adjust some things on the carb and it seems to be doing ok!
I didnt want to take it back to the mechanic because he didnt fix it the last time he had it, but said he did. I didnt want to pay $70 for a tow bill plus whatever he'd charge to get another non-running vehicle back. I dont mind working on it, when I think I know what it is I enjoy it, I just wanted some ideas of what it might be. I like a project, but haven't worked on cars so I didnt know where to start. |
|
Back to top |
|
|
ashman40 Samba Member
Joined: February 16, 2007 Posts: 15975 Location: North Florida, USA
|
Posted: Tue Jan 08, 2019 12:17 pm Post subject: Re: 72 Super having some trouble. Can anyone help? Thanks! |
|
|
CotyWeaver wrote: |
I was told that there was only supposed to be 8.75 to 9 volts coming out of the coil. I had time to check it, it was 11 volts when it was off and all over the place running. |
There is a spec for the voltage at the #15 (+) terminal of the ignition coil. It should be close to battery voltage. Ideally, if the battery reads 12.6v with the ignition switch ON, I'd expect to get a voltage reading at the #15 (+) terminal of around 12.5v.
Any voltage reading taken at the #1 (-) terminal of the coil while the engine is running is pretty much meaningless. There is no spec for it so what are you comparing it against?
CotyWeaver wrote: |
A friend told me I needed a ballast resistor to fix that because it didn't sound like the coil had an internal one... |
The stock ignition needs 3-4ohms of resistance between the incoming current on the #15 terminal of the coil and the points. Most stock ignition coils have an internal ballast resistor that provides this 3-4ohms.
Disconnect all the wires from your coil.
Set your meter to read resistance.
Place one probe on the + and one probe on the - terminals of the coil. You should get a resistance reading in the 3-4ohm range. Is the reading is too low, add an external ballast resistor on the + terminal to add the number of ohms needed to get you into the 3-4ohm range. For example, if your coil had an internal resistance of 1.5ohms you want to add a 1.5-2.5ohm ballast resistor.
This resistance is critical for BOTH a stock mechanical points as well as electronic points. The resistance reduces the current that passes thru the ignition coil primary windings and prevents the points and condenser from being damaged from too much current. It can be worse for electronic points that require 3-4ohms of primary resistance. They burn up when matched with low resistance coil.
CotyWeaver wrote: |
I took it to another mechanic that assured me he could fix it, no problem. A week later he tells me to pick it up, it was just the condenser. The next day, the problem came back. Won't idle long, roughly when it does, and shuts down giving it any gas at all. |
If you are burning thru condensers you could have a problem with too little resistance in the coil. Run the above test to confirm. You could also just be running into bad condensers. I would have asked in the past if you are running Bosch parts, but recent Bosch condensers have had a bad rep.
You might want to try Beck & Arnley ignition parts. I've had good luck with them in the past, but don't know if their quality has slipped as well.
If not the condenser I'd suggest a look at the fuel tank outlet. I'm not sure if the 72 SB was one of the years that still had a screen at the bottom of the tank. If your tank is original it likely has decades of crud at the bottom of the tank. This eventually clogs the outlet. If your tank has a removable screen, you should remove it an flush the crud from the tank and lines.
Fuel starvation is most noticeable when you must maintain high rpms for a while. Take it to a long quiet road where you can drive w/o slowing for a good distance. Stay in 3rd and let the rpms run high 3000rpm but remain constant. This will tend to put a strain on the fuel delivery. If the fuel lines are restricted the carb fuel bowl will run dry. As soon as the engine dies, pull over. Don't restart the engine or let it idle. You want to confirm if the carb has run dry. Once you are off the road remove the top of the carb and look at the fuel level in the bowl. If the bowl is empty you know you have a fuel delivery problem and not an ignition problem. _________________ 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!}
Last edited by ashman40 on Tue Jan 08, 2019 12:56 pm; edited 1 time in total |
|
Back to top |
|
|
Buggeee Samba Member
Joined: December 22, 2016 Posts: 4391 Location: Stuck in Ohio
|
|
Back to top |
|
|
CotyWeaver Samba Member
Joined: September 16, 2018 Posts: 15 Location: Tennessee
|
Posted: Tue Jan 08, 2019 3:31 pm Post subject: Re: 72 Super having some trouble. Can anyone help? Thanks! |
|
|
Thanks Buggeee!
Thanks as well Ashman, I have some things to check out.
It was running pretty well yesterday, but then I drove it this morning... There was a shudder, a pop, and now a weird twangy rattle. I notice it more on hills. I HAD to make it an hour away today and coming back I noticed it was impossible to shift to third at times and the rattle worsened. I'll be taking it back to the second mechanic in the next couple of days i guess... |
|
Back to top |
|
|
|