Cold Air Idle Fix--Step-by-step for 34PICT/3!

Bugzai wrote:

> - Turn the Volume Control Screw (smaller, lower screw) in or out
> slowly to give the highest idle speed. Turn it in SLOWLY in to drop
> the idle speed by about 30rpm. (This sets the mixture a fraction rich
> like it's supposed to be--screwing it in means less air-richer mix).

I thought this a typical mixture screw that makes it richer when you
turn it out (CCW). I pretty sure mine works this way on both the
H30/31 and the 34PICT3 cause you can smell it.


RT
--
E-mail=fullname-at-telus.net

Raymond Lowe wrote:
>
> Bugzai wrote:
>
> > - Turn the Volume Control Screw (smaller, lower screw) in or out
> > slowly to give the highest idle speed. Turn it in SLOWLY in to drop
> > the idle speed by about 30rpm. (This sets the mixture a fraction rich
> > like it's supposed to be--screwing it in means less air-richer mix).
>
> I thought this a typical mixture screw that makes it richer when you
> turn it out (CCW). I pretty sure mine works this way on both the
> H30/31 and the 34PICT3 cause you can smell it.
>
> RT



That's right. Turn IN for leaner, turn OUT for richer.

Other than that the advice was dead on.

Jan

> - Turn the Volume Control Screw (smaller, lower screw) in or out
> slowly to give the highest idle speed. Turn it in SLOWLY in to drop
> the idle speed by about 30rpm. (This sets the mixture a fraction rich
> like it's supposed to be--screwing it in means less air-richer mix).
> - Use the Bypass Screw (larger, higher screw) to reset the idle to
> 850rpm.
>
> Done. I did it!
>
> Tom

You may need a new carb.
The throttle bushing may be so worn that air is leaking through and
cannot be set acurately.
Get a 34PICT3 non smog carb.
I have seen them advertised for as low as $129.00 US. Try California
Import at www.cip1.com.

My reference books and manuals say that turning the small screw in
makes a leaner setting.
Too lean is not good. It can fry the engine.
Better a little too rich than too lean. You pay more at the pump but
that is easier than paying for a new engine.
Here is how I adjust me carb:
Set the valves too .006 inch gap with engine cold from sitting
overnight.
Change the plugs.
Set the choke.
Actually, I set my choke to the minimal setting for cold weather and
set to almost none in warm or hot weather.
Warm it up and set the timing.
On my '73 Beetle with Type I 1600cc DP I set it to 7.5 degrees btdc.
Warm it up some more.
Drive it 5 miles or more until the oil temp has reached 158 degrees
F.
Adjust idle to 850 to 900 rpm.
Shut it off.
Carefully turn the small screw all the way in but do not grind it in
and damage the seat.
Turn the small screw out 3 turns.
Hook up a tach and turn the small screw in until the idle drops about
30 rpm.
Slowly turn the small screw out 1/4 turn.
This is added insurance that the mixture is not to lean.
Recheck the idle and timing.
Hey! It works for me!
jplikesm73vwbttl

For years I was plagued by stalling on by '74 Beetle (34PICT/3 carb) in
cold weather (air temperature below 10oC). The car would start fine,
but stall as soon as the choke opened. I finally discovered that the
problem was a failure of the thermostated vacuum valve that controls the
hot air/warm air mix going into the air cleaner. Only cold air was
reaching the carb, which according to the manual should receive air at
55oC. My cheap fix is simply to force the air cleaner to take in only
hot air in the winter, and only cold air in the summer. I'm sure Bobb
Hoover wouldn't approve of this fix- it wastes gas and may introduce
some risk of overheating the engine- but it has eliminated the stalling
problem. Recently I noticed that an apparently identical valve
is used on the A2 Golf, so there may be an abundant supply of spare
parts in junkyards.

Garry
Ottawa, Canada

Bugzai wrote:
> Hi all,
>
> Thought I'd possibly return a few favors and post a solution that
> worked for me...as opposed to asking yet another question. Thanks to
> posts by Rod Boardman, Jan Andersson, and others.
>
> Bug: 75 SB, converted to carb, 34PICT/3.
>
> Problem: Would start up fine in cold weather (36-50 degrees F), but
> would stall after auto choke disengaged. Located in Ottawa, Canada.
>
> After reading a bunch of old RAMVA posts (clicked Search), the
> following worked for me:
>
> - With engine cold, adjust valves (mine already were)
> - Check points are at a 0.016" gap (mine already were)
> - Adjust timing to 5 degrees ATDC (mine already was)
> - Take air breather off and inspect carb., particularly the choke
> 'flap'. (with Muir book so I could figure out which component was
> which)
> - Start bug and watch choke flap close/open and the time it starts to
> stall. Play with choke flap to see what it takes to prevent stall.
> (see how much play I'm dealing with)
> - Put palm over top of carb when running. Attempt to create vacuum and
> suck dirt out of fuel and air channels. Also check for air leaks
> (stalled immediately so no air leaks assumed).
> - Re-adjust auto-choke on right-side of carb. Loosen 3 small screws.
> Rotate the inner choke cylinder counter-clockwise, so that the part of
> it facing you moves down. This causes the choke to be stronger and
> stay on longer. Fasten screws. (come spring/summer, readjust
> auto-choke back).
> - Start engine and test. Put air breather back on.
> - Make sure idle cut-off valve is working...(did not have to do this
> step so I'll skip the steps--search for this topic if it relates to
> you).
> - Set carb by first warming up engine so that choke is fully open.
> Turn engine off.
> - Unscrew Fast Idle Adjustment Screw until it clear of the stepped
> cam. Screw it in so it JUST touches the bottom step of the cam. Screw
> in another 1/4 turn (this sets the throttle butterfly to the required
> .004 inch).
> - Turn the Volume Control Screw (smaller screw on the left side of
> carb) until it bottoms. GENTLY. Unscrew it 2.5 turns.
> - Attach dwell-tachometer (or use your ears and listen).
> - Start engine and use the Bypass Screw (larger screw) to set idle
> speed to 850rpm (before this step I had to bottom out Bypass Screw and
> unscrew 3 turns as a starting point since I frigged around with it too
> much before).
> - Turn the Volume Control Screw (smaller, lower screw) in or out
> slowly to give the highest idle speed. Turn it in SLOWLY in to drop
> the idle speed by about 30rpm. (This sets the mixture a fraction rich
> like it's supposed to be--screwing it in means less air-richer mix).
> - Use the Bypass Screw (larger, higher screw) to reset the idle to
> 850rpm.
>
> Done. I did it!
>
> Tom

Garry Tarr > wrote in message >...
> My cheap fix is simply to force the air cleaner to take in only
> hot air in the winter, and only cold air in the summer. I'm sure Bobb
> Hoover wouldn't approve of this fix-

---------------------------------------------------------

I believe you will find the most common advice offered by 'Bobb
Hoover' is the need to think for yourself.

As a matter of fact, Volkswagen offered a 'High Latitude' package for
engines in Arctic climates that included chromed valve covers, a
variety of shutters that fitted over the inlet to the blower housing,
an insulated blanket for the bottom of the sump and an air cleaner
that offered full-time heating of the incoming air.

When VW introduced the 'automatic' choke they provided three heating
elements to be used, as appropriate, for arctic, temperate and tropic
climates. Dealer bulletins and Service Notes pointed out that for
some regions the range of winter-summer temperature was so wide that
the normal twice-yearly adjustment of the choke element (see the
manual) would not be sufficient. In those cases the element was
simply swapped for one of the proper range.

Thinking for yourself is good. But it's naive to assume Volkswagen
was not aware of problems inherent to cold-weather operation.

-Bob Hoover