72' Beetle with idle problems

I recently purchased a 72' Beetle. After driving the vehicle for about 10
minutes the idle becomes rough and the car dies if I don't continually tap the
accelerator. Also, the electric fuel pump vibrates extremely heavily every so
often. (lack of fuel?)

I've checked the spark plugs, replaced the condenser and distributor points,
and the carburetor looks brand new. When I take the fuel line off the
carburetor the fuel pump appears to be pumping an adequate flow of gasoline
without blockage or any visible dirt or other gunk. The local shop recommended
that I remove the gas tank and look for any debris or anything else that might
be causing blockage. Any advice is appreciated.

Thanks Jason

Flgstonia wrote:
>
> I recently purchased a 72' Beetle. After driving the vehicle for about 10
> minutes the idle becomes rough and the car dies if I don't continually tap the
> accelerator. Also, the electric fuel pump vibrates extremely heavily every so
> often. (lack of fuel?)
>
> I've checked the spark plugs, replaced the condenser and distributor points,
> and the carburetor looks brand new. When I take the fuel line off the
> carburetor the fuel pump appears to be pumping an adequate flow of gasoline
> without blockage or any visible dirt or other gunk. The local shop recommended
> that I remove the gas tank and look for any debris or anything else that might
> be causing blockage. Any advice is appreciated.
>
> Thanks Jason

Disagree (respectfully:-)

BTW, the electric fuel pump is not stock; '72 engines had
a mechanical pump to the right of the distrib.

Dunno where your pump is mounted, but the preferred location is
under the fuel tank, mounted on shock absorbing insulators.

It's very possible that the pump is putting out too *much*
pressure, rather than not enough. That will cause minor flooding
which is most noticeable at idle.

I'd hook a fuel pressure gauge between pump and carb inlet to see.
3 PSI is more than enough. A regulator may be in order.

Flooding can also occur if the float needle valve is loose or
not sealing positively.

Strongly recommend picking up some kind of shop manual for this car.
(Bentley, Haynes, Muir)
Even if you don't plan to do all your own work, you need some
reference material.

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

>From: flgstonia

>After driving the vehicle for about 10
>minutes the idle becomes rough and the car dies if I don't continually tap
>the
>accelerator. Also, the electric fuel pump vibrates extremely heavily every
>so
>often. (lack of fuel?)
>

i'd guess either a bad idle shutoff solenoid or a tank venting problem....try a
google group search on this group for those problems...plenty of reading....

http://groups.google.com/groups?hl=e...c.autos.makers.
vw.aircooled




-------------------
Chris Perdue
"I'm ever so thankful for the Internet; it has allowed me to keep a finger in
the pie and to make some small contribution to those younger who will carry the
air-cooled legend forward"
Jim Mais
Feb. 2004

> I've checked the spark plugs, replaced the condenser and distributor points,
> and the carburetor looks brand new. When I take the fuel line off the
> carburetor the fuel pump appears to be pumping an adequate flow of gasoline
> without blockage or any visible dirt or other gunk. The local shop recommended
> that I remove the gas tank and look for any debris or anything else that might
> be causing blockage. Any advice is appreciated.

Where is the pump located? Ideally the low-pressure electric pumps
should be installed below the fuel tank. The facet pump(square, noisy
as hell) is a decent enough pusher but it doesn't do a good job of
pulling fuel, hence the reason it needs to be under the tank so
gravity will help keep it fed.

However, in all honesty, I've personally had nothing but bad luck with
the electric pumps. They're noisy, and they don't seem to hold up
well. The stock mechanical fuel pump works just fine. Installing one
is a cinch, you'll need locate the proper pump, pushrod, mounting
block, fuel filter, and fuel line. Install the filter between the fuel
outlet on the driver side frame rail and the rear tin where the VW
fuel pipe comes through. Do not install a filter on the pressure-side
of the pump. When you get ready to install the pump you'll want to
coat the gaskets with RTV, and you need to pack the bottom of the fuel
pump with wheel bearing grease.

Check with John @ www.aircooled.net for your parts. He'll set you up
with what you need.

Chris

I am combating a simular problem. Check the tank first. An easy check is to
crack the gas cap then take low pressure air hose and blow air through fuel
line before pump back into tank. If this clears and your bug runs good. Then
drain the tank and remove and clean. Trust me!!! I just walked back in the
house lesss than an hour ago doing the same thing to my 74 super beetle. Now
it runs and it won't cut off after 10-15 mins.
"Flgstonia" > wrote in message
...
>I recently purchased a 72' Beetle. After driving the vehicle for about 10
> minutes the idle becomes rough and the car dies if I don't continually tap
> the
> accelerator. Also, the electric fuel pump vibrates extremely heavily
> every so
> often. (lack of fuel?)
>
> I've checked the spark plugs, replaced the condenser and distributor
> points,
> and the carburetor looks brand new. When I take the fuel line off the
> carburetor the fuel pump appears to be pumping an adequate flow of
> gasoline
> without blockage or any visible dirt or other gunk. The local shop
> recommended
> that I remove the gas tank and look for any debris or anything else that
> might
> be causing blockage. Any advice is appreciated.
>
> Thanks Jason
>