Stalling Problem

Looking for a little help with what I think is an ignition problem. A
friend of mine has a 73 Super Beetle with an Autostick and it will
randomly stall. It can happen anytime, but doesn't always do it. It
does seem to happen only when engine is warmed up, but sometimes it
runs perfectly. At night when it happens if you turn the lights on
while idling it will stall immediately, but you can keep it running by
giving it gas. It can also happen when shifting into gear. Points,
condenser, cap and rotor have all been replaced. Timing has been
checked and valves are adjusted. We're going to take a look at it this
weekend and just thought I get some opinions on where to look.

Thanks

Matt

wrote:
> Looking for a little help with what I think is an ignition problem. A
> friend of mine has a 73 Super Beetle with an Autostick and it will
> randomly stall. It can happen anytime, but doesn't always do it. It
> does seem to happen only when engine is warmed up, but sometimes it
> runs perfectly. At night when it happens if you turn the lights on
> while idling it will stall immediately, but you can keep it running by
> giving it gas. It can also happen when shifting into gear. Points,
> condenser, cap and rotor have all been replaced. Timing has been
> checked and valves are adjusted. We're going to take a look at it this
> weekend and just thought I get some opinions on where to look.
>
> Thanks
>
> Matt
>
My vote: minor carb flooding.
Very common in summer. Hot fuel in carb bowl
percolates out or is forced out the accel jet.
Makes idle mixture very rich and the slightest
load on the engine (more Amps from Gen or shift into gear)
causes stalling.

NOTE: This is NOT "vapor lock".

There is no "good" fix for it.
Raising carb on an insulating gasket may help.
Adding a fiber washer under the float needle valve may help
(lowers fuel level in bowl).
Replacing needle valve may help.
Adjusting idle mixture leaner (small screw) may help.
Raising idle speed may help.

--

Speedy Jim
http://www.nls.net/mp/volks/

wrote:
> Looking for a little help with what I think is an ignition problem. A
> friend of mine has a 73 Super Beetle with an Autostick and it will
> randomly stall. It can happen anytime, but doesn't always do it. It
> does seem to happen only when engine is warmed up, but sometimes it
> runs perfectly. At night when it happens if you turn the lights on
> while idling it will stall immediately, but you can keep it running by
> giving it gas. It can also happen when shifting into gear. Points,
> condenser, cap and rotor have all been replaced. Timing has been
> checked and valves are adjusted. We're going to take a look at it this
> weekend and just thought I get some opinions on where to look.
>
> Thanks
>
> Matt

I'm no bug expert so take this with a grain of salt:
You say it frequently stalls when your turn the lights on?

I'd check the voltage across the battery and the coil. They should
pretty much be equal and with an alternator read over 14V.
Kick the lights on and measure again.
While it may be charging fine, perhaps you have a bad ground in your
headlight path somewhe With a bad ground, the current finds another
way to return which causes an unexpected voltage drop in other circuits
(causing maybe the coil to starve).

Remco

Remco wrote:
> wrote:
> > Looking for a little help with what I think is an ignition problem. A
> > friend of mine has a 73 Super Beetle with an Autostick and it will
> > randomly stall. It can happen anytime, but doesn't always do it. It
> > does seem to happen only when engine is warmed up, but sometimes it
> > runs perfectly. At night when it happens if you turn the lights on
> > while idling it will stall immediately, but you can keep it running by
> > giving it gas. It can also happen when shifting into gear. Points,
> > condenser, cap and rotor have all been replaced. Timing has been
> > checked and valves are adjusted. We're going to take a look at it this
> > weekend and just thought I get some opinions on where to look.
> >
> > Thanks
> >
> > Matt
>
> I'm no bug expert so take this with a grain of salt:
> You say it frequently stalls when your turn the lights on?
>
> I'd check the voltage across the battery and the coil. They should
> pretty much be equal and with an alternator read over 14V.
> Kick the lights on and measure again.
> While it may be charging fine, perhaps you have a bad ground in your
> headlight path somewhe With a bad ground, the current finds another
> way to return which causes an unexpected voltage drop in other circuits
> (causing maybe the coil to starve).
>
> Remco

Btw, with "measuring across the coil", I mean measusing across the
primary of the coil of course (Just making sure you don't zap your
multimeter or yourself.
Basically measure across the slip on contacts.

Thanks for the replies. Hopefully we'll a chance to look at it this
weekend and I'll post back if we find anything. He has a rebuilt carb
that he is going to put on and maybe that will help if it's fuel
related.

Thanks

Matt

Check the rubber boots that connect the the carb doohiky (good lingo here)
to the headers, just above the risers. If they are cracked you leak air into
your mixture and the engine acts weird.
http://funkie.ramva.org/1973SB/dp_riser1.jpg

> wrote in message
oups.com...
> Looking for a little help with what I think is an ignition problem. A
> friend of mine has a 73 Super Beetle with an Autostick and it will
> randomly stall. It can happen anytime, but doesn't always do it. It
> does seem to happen only when engine is warmed up, but sometimes it
> runs perfectly. At night when it happens if you turn the lights on
> while idling it will stall immediately, but you can keep it running by
> giving it gas. It can also happen when shifting into gear. Points,
> condenser, cap and rotor have all been replaced. Timing has been
> checked and valves are adjusted. We're going to take a look at it this
> weekend and just thought I get some opinions on where to look.
>
> Thanks
>
> Matt
>