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Dubskii
Samba Member
Joined: March 03, 2010
Posts: 385
Location: So Cal
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 Posted: Sun Feb 15, 2015 11:10 pm Post subject: Stalling Coming to a Stop |
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| My 69 starts, idles and runs fine. However, today as I was approaching a stop sign, I downshifted and then shifted to neutral to stop. As I did that the generator and battery light came on and then it stalled. It started right back up and no problems getting home. Not sure what to look at to fix this. |
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Wasted youth
Samba Member
Joined: July 06, 2012
Posts: 5134
Location: California's Hot and Smoggy Central Valley
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| Posted: Sun Feb 15, 2015 11:59 pm Post subject: |
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| This is often caused by a vacuum leak associated with your vacuum operated brake booster, if applicable. The vacuum energy for the booster operation comes from the intake manifold of your engine, normally not a problem at all if the system is tight. If there is a leak in the vacuum diaphragm, tubing and hose system, then you create a vacuum leak in the engine intake side when you press the brake pedal (activating the booster vacuum circuit), causing an engine stall. |
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SGKent 
Samba Member
Joined: October 30, 2007
Posts: 41031
Location: Citrus Heights CA (Near Sacramento)
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| Posted: Mon Feb 16, 2015 12:33 am Post subject: |
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check your mixture. If it goes too lean or too rich when the throttle closes that can cause it to die. Check the choke to be sure it is opening properly and make sure the engine is warm before you adjust it. If you are in an area that was abnormally cold and you don't have preheat you may just have to increase the idle and mixture a little in cold weather.
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“Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin |
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Dubskii
Samba Member
Joined: March 03, 2010
Posts: 385
Location: So Cal
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| Posted: Mon Feb 16, 2015 6:58 am Post subject: |
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| Last night I was poking around making sure everything was secure on the carburetor and discovered it wasn't. The electromagnetic cutoff valve was pretty loose. I backed it all the way out, cleaned it up and screwed it back nice and snug. I am hoping this was the culprit. If not I will look into the choke and booster lines as suggested. Thanks! |
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Dubskii
Samba Member
Joined: March 03, 2010
Posts: 385
Location: So Cal
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| Posted: Mon Feb 16, 2015 8:47 am Post subject: |
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I don't see any vacuum lines on the intake or carb... |
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Wasted youth
Samba Member
Joined: July 06, 2012
Posts: 5134
Location: California's Hot and Smoggy Central Valley
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| Posted: Mon Feb 16, 2015 9:18 am Post subject: |
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| Dubskii wrote: |
| I don't see any vacuum lines on the intake or carb... |
Yeah... in fact, I think I see a cap. |
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SGKent
Samba Member
Joined: October 30, 2007
Posts: 41031
Location: Citrus Heights CA (Near Sacramento)
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| Posted: Mon Feb 16, 2015 11:15 am Post subject: |
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| Dubskii wrote: |
| Last night I was poking around making sure everything was secure on the carburetor and discovered it wasn't. The electromagnetic cutoff valve was pretty loose. I backed it all the way out, cleaned it up and screwed it back nice and snug. I am hoping this was the culprit. If not I will look into the choke and booster lines as suggested. Thanks! |
an air leak there would certainly affect the mixture.
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airschooled
Air-Schooled
Joined: April 04, 2012
Posts: 12721
Location: on a bike ride somewhere
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| Posted: Mon Feb 16, 2015 12:05 pm Post subject: |
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I agree, from personal experience, that a loose cutoff solenoid can cause issues exactly like the one you have. I can not promise that you don't have any other issues though…
| Dubskii wrote: |
[img]
I don't see any vacuum lines on the intake or carb... |
You don't need a vacuum line to have a vacuum leak. Any connection of any two materials on the intake system can leak and create one, including but not limited to:
- those rubber caps on your carb
- a loose cutoff solenoid
- loose intake manifold pieces
- loose carburetor nuts/bad gasket
- loose throttle shaft bushings
Is that a picture of your engine compartment? Can we make a few suggestions?
- Wire your air cleaner's intake flap in the "warm air intake" position when it is cold enough outside to wear pants and long sleeves. This will improve your bus' performance while the engine is warming up, as well as reduce wear during warm up.
- Move your fuel filter to directly above the transaxle. That way the weight of it won't be trying to pull the fitting out of the carburetor. Then reroute your fuel line so it does not chafe on the coil No touchy allowed anywhere except directly on fittings.
-Shorten your heater hoses so they take a direct path from fan shroud to heat exchangers. If you get them to maybe an inch longer than they exactly need to be, they will compress like a spring and that tension will hold them on without hose clamps. Ingenious design, really…  You'll also get MUCH better heater airflow, which I think you'll enjoy this time of year.
Apart form those three things, it looks like you've got a real winner there. Have fun with it. 
Robbie
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Abscate
Samba Member
Joined: October 05, 2014
Posts: 22639
Location: NYC/Upstate/ROW
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| Posted: Tue Feb 17, 2015 8:19 am Post subject: |
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No brake booster (if stock) on the 1969.
It does sound like a carb solenoid possibility, but a lean mixture will also stall on run-down. Vacuum leaks, carb leaks, intake manifold seal leaks all worth checking.
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Wasted youth
Samba Member
Joined: July 06, 2012
Posts: 5134
Location: California's Hot and Smoggy Central Valley
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| Posted: Thu Feb 19, 2015 12:15 am Post subject: |
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 Status?
Remember, posting your results will help someone in the future diagnose their problem.
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Dubskii
Samba Member
Joined: March 03, 2010
Posts: 385
Location: So Cal
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| Posted: Sat Feb 21, 2015 12:32 pm Post subject: |
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***UPDATE***
Tightening the cutoff valve worked. Runs like a champ again. Haven't had a stalling episode since (Knock on wood).
Asiab3...Working on your recommendations. Couple things. Where can I get those vacuum caps and can you post a pic of your fuel filter/line setup? |
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Wasted youth
Samba Member
Joined: July 06, 2012
Posts: 5134
Location: California's Hot and Smoggy Central Valley
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| Posted: Sat Feb 21, 2015 10:11 pm Post subject: |
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| Thanks for updating... I found a bag of mixed size vacuum caps and also a pack of Tees at my FLAPS and you might find some good pics of proper fuel line set ups in the Samba gallery |
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airschooled
Air-Schooled
Joined: April 04, 2012
Posts: 12721
Location: on a bike ride somewhere
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| Posted: Sun Feb 22, 2015 1:16 am Post subject: |
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Thanks for the update. Like Wasted youth said, future bus owners read old threads and remember fixes like this.
| Dubskii wrote: |
Where can I get those vacuum caps and can you post a pic of your fuel filter/line setup? |
I like AutoHausAZ for little stuff like tune-up parts and odds and ends. Their vacuum caps for an air-cooled VW are BMW brand, and they last much longer than the cheapo caps from AutoBone.
Caps for 3.5mm (small) vacuum lines:
http://www.autohausaz.com/pn/11611437560
Caps for 5mm (large) fuel size lines, but some manifolds have this:
http://www.autohausaz.com/pn/11611437694
The vehicle selection process and linking system on their site is a little archaic, but you'll get the hang of it quickly. Your carb looks like a 30/31pict, which is a hybrid of a 34pict3 (1971) and a 30pict3 (1970). For most engine parts you can select a 1969 model for their site, but for some carb stuff (like a spare cutoff solenoid!) you'll want to select 1971 carb parts.
Here is my top end a few years ago; it's the only clear picture I have of the fuel lines. Note, the distributor advance line should be a metal pipe with a droop in it, and I have a vacuum retard line as well. The fuel line does not touch ANYTHING so it does not chafe. Just like the heater hose, I leave a little extra length so there's a little inherent spring in the line. This relieves some of the tension on the carb fitting, which on mine is threaded into the carb and flanged so the line can't pop off. No engine fires for me.
Here are my heater hoses, no clamps needed if you get the length just right. You want the hoses trying to expand to hold them in place. (Ignore the mess of vacuum hoses; the bus drives much smoother with the emissions equipment. Also ignore my rats nest of wiring, I was mocking up a third brake light, tach, electronic distributor, and engine compartment LED strips when I took this.)
For the fuel filter, lay directly under your transaxle. Give it a hug behind the drive shafts. Where your fingers touch is where the filter goes. You want it between the tank outlet and the engine firewall WHERE YOU HAVE A GROMMET RIGHT? Above the transaxle gets it out of the way of road debris, and it also makes sure if the filter ruptures it doesn't rupture and pour gas all over the #3 exhaust pipe.
My three cents,
Robbie
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Learn how your vintage VW works. And why it doesn't!
One-on-one tech help for your Volkswagen:
www.airschooled.com |
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HarryFD
Samba Member
Joined: February 24, 2012
Posts: 751
Location: Portland, OR
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| Posted: Mon Feb 23, 2015 10:12 pm Post subject: |
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Glad you found the source.
I had some similar incidents with my 1970. Found them to be:
-First time: Loose shut off valve; and
-Second time: Bad float valve.
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1973.5 911 Targa
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