My Bug is Still Hesitating Badly...
vwlarry
'73 Auto-Stick Super Beetle continues to hesitate in the lower speeds after
it warms up. My mechanic and I have checked the torque of the upper head
bolts, carb, gas filters, carb base gasket, points & rotor, timing, valves,
vacuum advance, replaced leaky exhaust, etc. etc. etc, and we still can't
find a cause for the hesitation. It starts to hesitate after driving it for
a few minutes. When it's cold and when I'm driving over 30-35 mph, it seems
to accelerate fine, but when I stop or slow down and then re-accelerate, it
has a serious flat spot. When this happens, I let off the gas pedal a bit
and then slowly re-accelerate to gain speed again.
Any suggestions??? I'm going crazy trying to find this gremlin.
TIA,
--
Larry S.
'73 Super Beetle
'73 Westfalia
'98 New Beetle
Speedy Jim
Did you confirm that the manifold preheat pipe *actually* gets hot
at both ends (after a short drive)? Without the heat, raw fuel
just lays in the manifold when you "step on it".
Also, see if the accel pump begins to dischg as soon as the
throttle begins to open. Often, the linkage is so worn that
the pump doesn't start to move until much later.
Speedy Jim
http://www.nls.net/mp/volks/
Baja Mike
--
MIKE
Baja1641
www.offroadvws.com !
"vwlarry" <la...@yahoo.com> wrote in message
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Alan Nelson
--
Alan Nelson
www.boatcop.com
___
/___\ Proud Owner of a
(0\_|_/0) 1969 VW Bug
U U "Tizzy"
"vwlarry" <la...@yahoo.com> wrote in message
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Joao Eliseu
> Any suggestions??? I'm going crazy trying to find this gremlin.
>
found that the Pilot Jet witch is in the right side of the carb, was
swap with the one (I don't know the name) witch makes 45º with the end
of the car. I hope you understand what I mean. The hesitation is
because there isn't enough fuel.
Looking from the top.
----Right side
\
\
\
45º
Joao
72 Super
Eduardo K.
>vwlarry wrote:
>
>Did you confirm that the manifold preheat pipe *actually* gets hot
>at both ends (after a short drive)? Without the heat, raw fuel
>just lays in the manifold when you "step on it".
>
I have the same hesitation, and sure enough, just chequed
and manifold only gets hot on the right side...
time to take it out, I guess... easy without taking the engine out?
its a single port...
--
Eduardo Kaftanski | Win95 & Win98: n. 32 bit extensions and a graphical
e...@nn.cl | shell for a 16 bit patch to an 8 bit operating system
http://e.nn.cl | originally coded for a 4 bit microprocessor, written by
| a 2 bit company, that can't stand 1 bit of competition.
vwlarry
--
Larry S.
'73 Super Beetle
'73 Westfalia
'98 New Beetle
"Alan Nelson" <ane...@rraz.net> wrote in message
news:abtm3...@enews4.newsguy.com...
vwlarry
I haven't yet run the Bug today, but I will check the manifold pre-heat pipe
when I take her out for a spin later today.
I did check the accelerator pump (car not running) and it does squirt gas as
soon as the throttle is opened. However, I did notice some gas seeping from
the right side (not the left) of the throttle shaft just above the
accelerator pump adjustment thingy when I was opening and closing the
throttle. I checked for play in the throttle shaft and there is a little
side to side movement in the throttle shaft. If the car is not running,
would it be normal for some gas to seep out from the right side of the
throttle shaft when squirting raw gas into the bowl? If not, could this
possibly be the cause of the hesitation? Lately, I did notice that the idle
seemed to wander a bit, but not anything really noticeable.
--
Larry S.
'73 Super Beetle
'73 Westfalia
'98 New Beetle
"Speedy Jim" <vo...@nls.net> wrote in message news:3CE257...@nls.net...
Speedy Jim
There can be a number of reasons for it not heating.
The pipe may be blocked with carbon deposits. You have to take the
muffler off to find out. Then either blow compressed air thru
or run a wire thru the pipe.
If it appears to be clear, see if the 2 flanges where the muffler
attaches were clear and the gaskets open.
Lastly, the placement inside the muffler of the "pigtail tube",
which puts exhaust gas into one tailpipe, is critical.
Many times, the factory squashes the little tube or welds
it in place off-center.
Finally, the depth-of-insertion of the tailpipe tip matters.
(It varied by year, check the manual.) But the end of the
tailpipe must be just slightly back from the little tube end.
That creates the venturi necessary to suck the gas out of the tube.
You can experiment by varying the tailpipe depth and seeing the
big difference it makes in the temp of the manifold.
Speedy Jim
http://www.nls.net/mp/volks/
BusStopVW
Bus and 66Bug. New carbs fixed both of them.
vwlarry
Both sides of my manifold pre-heater pipe are hot.
The only thing left is the small gas seep from the right side of the
throttle shaft linkage. It doesn't appear to be seeping gas when the car is
running. Only when I shut it off and then manually open and close the
throttle does it start to seep from the right side of the throttle shaft. If
it's sucking a small amount of air from the right side, could that be enough
to cause my hesitation???
--
Larry S.
'73 Super Beetle
'73 Westfalia
'98 New Beetle
"Speedy Jim" <vo...@nls.net> wrote in message news:3CE2B9...@nls.net...
Speedy Jim
(I imagine the gas leaking is normal with a loose shaft.)
I'm a pretty empirical kind of person and I would probably
try a glob of silicone caulk on the bushing/shaft to see
if sealing it made any difference:-)
Jim
vwlarry
--
Larry S.
'73 Super Beetle
'73 Westfalia
'98 New Beetle
"BusStopVW" <buss...@aol.comnojunk> wrote in message
news:20020515161944...@mb-ft.aol.com...
AmaBaja
An air leak may lean out the mix with the choke on, as air comes in below
the choke. When the engine is warmed up the choke should be off, less of an
air leak. But that usually doe not make much of a difference unless there
is a huge leak.
Another thing, Jetting must be done correctly, a size change in a idle jet
makes a bigger difference then adjusting the fuel mixture screw. Look here
for the stock jets for you model solex.
http://www.ramva.org/techdata/Solex%20Jetting.html Your Idle jet for the 34
PICT 3 should be about 55.
I had a similar problem, changed gets and adjusted carb and hesitation went
away. Usually involves lots of adjustments and test drives. Well I should
say it took me a few hours of playing to get it right. Can also be dirty of
blocked jets.
vwlarry <la...@yahoo.com> wrote in message
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AmaBaja
a 32 PICT 3 same jet arrangement. thanks for confirming my suspicions. but
do you know the correct size for the 45 deg jet? and what it does?
Allan
Joao Eliseu <joao....@cadflow.pt> wrote in message
news:9efc7c62.02051...@posting.google.com...
vwlarry
because it ran fine for over a year before the hesitation started last week.
I may take the carb apart and blow some compressed air through the jets. The
carb was dipped and a kit installed when I got it a year ago, so it can't be
that dirty. My Bug also has two fuel filters which are both pretty clean.
--
Larry S.
'73 Super Beetle
'73 Westfalia
'98 New Beetle
"AmaBaja" <Alla...@mweb.co.uk> wrote in message
news:3ce2f...@news1.mweb.co.za...
Rob
Larry,
I've read this thread and here's my thoughts.
1. Air leak at the throttle shaft - you said you notice a little fuel
dribble out there when testing the accel pump. The test for an air
leak there is to get the engine hot (no choke) and idling, and squirt
some WD40 or similar (use the little straw to get real close) at both
sides of the throttle shaft - ANY increase in egine rpm and you know
you have an air leak. The 34PICT/3 is particularly sensitive to
these, and you will need to get the throttle shaft hole drilled and
bushed, or else replace the carby.
2. Jetting. With your set-up, you should have a 55 idle (right side),
127.5 or just maybe 130 main (bottom of float bowl) and a 75 or 80 air
correction jet (vertical brass screw wiith a hole in it - between
float bowl and main throat - have to take the carby top off to see
it).
3. Vacuum diaphragm not working right. Pull the dizzy cap off and
look at the points plate. Take each vacuum line off the CARBY in turn
and suck on it - the points plate should move a few degrees clockwise
(the retard) and a lot more anticlockwise (the advance). When you
suck on the advance line, place your tongue over the hole - if the
points plate stays still the diaphragm is OK, but if it drifts back to
the "rest" position the diaphragm is holed and isn't pulling in the
advance like it should (yes - this causes hesitation).
The retard vacuum line is connected to the FRONT (front is front of
car) of the canister on the distributor and the BACK of the
carburettor. The advance line is connected to the back of the
canister, and to the left side of the carby.
4. Heat riser - as Speedy says, if this is not getting warm/hot, then
the fuel tends to puddle in the manifold as you floor it, rather than
staying as a mist and getting to the cylinders - you get an momentary
lean mixture, which causes the stumbles. If the heat riser is
blocked, there's a procedure for cleaning it out on my web site
(below).
5. Timing not set right. With the double vacuum distributor, you must
set it at 900 rpm idle (850 for manuals, 900 for semi-autos) with the
engine hot (no choke) - at 5ATDC. If your pulley has only a single
notch on the engine (front) side rim, and no TDC dimple in the rear
rim, that notch is 5ATDC and you time that to appear opposite the
crank case split. If you have a different pulley you must determine
which mark is TDC so you can make a mark 11mm to the left of that for
5ATDC. If the timing is working right and the timing light still
connected, you can see it jump from 5ATDC to 7.5BTDC as you slowly
advance the throttle (timing mark jumps to the left about 18mm/ 0.75
inch), and from that point it should increase the advance (timing
marks move further to the left)both with increasing rpm (the
centrifugal part) and jumping about a little with throttle movements
(the vacuum advance part).
There's a full tune-up guide on my web site if yu need one - look for
the "two adjusting screw" procedure for your 34PICT/3.
6. Leak in the vacuum port line under the carb - this port supplies
vacuum to the reserviour on the left side of the engine bay, to
activate the clutch when you touch the gear stick. A leek there will
cause the engine to run lean and THAT causes hesitation at lower
speeds. As the airflow increases (speed increases) the leak become a
smaller proportion of the airflow, so it's not so noticable. Look for
bad rubber lines, both to the reserviour and from there to the clutch
operating canister.
Your general description of running OK when the engine is cold is
indicating to me (and other posters to I notice) that with the choke
on it's OK, but with the choke off, it's hestitating - that's a SURE
sign the engine is running lean for some reason, and the above points
might help pinpoint it.
Good hunting.
Regards
Rob
Rob and Dave's aircooled VW pages
Repairs and maintenance for the home mechanic
http://www.geocities.com/aussiebug1970/
Blocked
a fairly simple setup on my '61! One vacuum line, one diaphragm, and a
simple carburetor.
--
___
|___| '61 - VW
(o\_|_/o) Bug! No, I have NOT named my car!
_U_____U_
See it at <http://homepage.mac.com/marksis/.Pictures/Beetle2001.jpg>
vwlarry
definitely need to check the vacuum line from the reservoir to the clutch
cannister. I did check the vacuum port line under the carb to the reservoir,
but I don't recall checking the vacuum line to the cannister.
Thanks again for taking the time to put this list together.
--
Larry S.
'73 Super Beetle
'73 Westfalia
'98 New Beetle
"Rob" <auss...@start.com.au> wrote in message
news:50287ec9.0205...@posting.google.com...
DODGENUT1
My wife's 70 Ghia Aouto had the same problem. Would hesitate just off idle,
with just light accel. and also normal accel. My mech. also said it did some
searching at idle. His advice to me was if I could find a new carb for a
reasonable price do it. QWell I did, a 30/31 Pict and it runs like a new car.
Wow! Jack
1970 Ghia coupe
1951 Stude. Coupe
1935 Dodge 1/2 ton
Dave Brower
Dave
"vwlarry" <la...@yahoo.com> wrote in message
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