carb issues

installed a new carb on a 67 bug and tuned it according to john muir's
instructions. seems to run fine at idle (about 850-900rpm according to the
tach/dwell meter), but when i go from 0-5mph it feels jerky and
unresponsive. at 20mph and above it feels relatively fine, but at those low
speeds it feels like the car is choking for gas or something. when i have
the car stopped and out of gear and push on the gas it seems responsive
enough, but this isn't the case when it's in gear and it has a load on it.
am i missing something? is there another potential issue outside of the carb
(fuel pump)?
i'm committed to getting this fixed myself as it's my project car so i don't
need to rely on it for daily driving, but i don't know what the issue is at
this point.
thanks,
chris

aptpupil wrote:

> installed a new carb on a 67 bug and tuned it according to john muir's
> instructions. seems to run fine at idle (about 850-900rpm according to the
> tach/dwell meter), but when i go from 0-5mph it feels jerky and
> unresponsive. at 20mph and above it feels relatively fine, but at those low
> speeds it feels like the car is choking for gas or something. when i have
> the car stopped and out of gear and push on the gas it seems responsive
> enough, but this isn't the case when it's in gear and it has a load on it.
> am i missing something? is there another potential issue outside of the carb
> (fuel pump)?
> i'm committed to getting this fixed myself as it's my project car so i don't
> need to rely on it for daily driving, but i don't know what the issue is at
> this point.
> thanks,
> chris
>
>


1) Vacuum advance/timing.

2) Weak spark or breakdown of HT leads/rotor/cap/plugs.

3) Lack of manifold heat.

4) Accelerator jet (even though it's a new carb).

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

What model distributor are you using?. Like most cars VW,s need vacuum
advance to minimise the flat spot on acceleration. Apparently even more so
with latter carbs that run lean. I,d make sure of that once Speedies simpler
items are fixed.
Found an issue on my daily drive a few years ago. It had vacuum advance
but it worked poorly. Turned out to be a "depression" where the ball bearing
sits on bottom plate of points carrier in distributor. There,s a little
"spring" that locates the ball and because for the last 35 years it had
wobbled around in one spot it formed a dent which acted to lock the fixed
and movable plates of distributor together. Got a hobby grinder out ,
ground it away, polished with emery paper. Was just like a new one. If you
make sure all the items Speedy mentions you can pretty well be sure of a
cure.
Cheers
John

"Speedy Jim" > wrote in message
t...
> aptpupil wrote:
>
>> installed a new carb on a 67 bug and tuned it according to john muir's
>> instructions. seems to run fine at idle (about 850-900rpm according to
>> the tach/dwell meter), but when i go from 0-5mph it feels jerky and
>> unresponsive. at 20mph and above it feels relatively fine, but at those
>> low speeds it feels like the car is choking for gas or something. when i
>> have the car stopped and out of gear and push on the gas it seems
>> responsive enough, but this isn't the case when it's in gear and it has a
>> load on it. am i missing something? is there another potential issue
>> outside of the carb (fuel pump)?
>> i'm committed to getting this fixed myself as it's my project car so i
>> don't need to rely on it for daily driving, but i don't know what the
>> issue is at this point.
>> thanks,
>> chris
>
>
> 1) Vacuum advance/timing.
>
> 2) Weak spark or breakdown of HT leads/rotor/cap/plugs.
>
> 3) Lack of manifold heat.
>
> 4) Accelerator jet (even though it's a new carb).
>
> Speedy Jim
> http://www.nls.net/mp/volks/
>

..
..
John

1) Absolutely amazing comment. The great value of discussions
with people who have been driving the same cars for 30 years.

2) Many would never have thought about the ball-bearing on the
point plate of the distributor... causing the problem by wearing
a 30-year-dent/depression into the point plate.

3) That would certainly prevent the vacuum canister from pulling
and rotating the point-plate to give that extra timing advance
required to overcome the acceleration bog, or hesitation, which
is so irritating in the 050 non-vacuum distributers.

4) Excellent comment, and cure, John.

5) And yes, Speedy's recommenations are superb also..... but
aren't they always. Speedy... and Jan.... and Bob Hoover... and
others - great members of the Beetle community.

Ross Virgin
Toronto, Canada
(where Beetles can drive through 6 feet of snow, and never
get stuck)
..
..
..
On Apr 3, 3:39*am, "John" > wrote:
> What model distributor are you using?. Like most cars VW,s need vacuum
> advance to minimise the flat spot on acceleration. Apparently even more so
> with latter carbs that run lean. I,d make sure of that once Speedies simpler
> items are fixed.
> * Found an issue on my daily drive a few years ago. It had vacuum advance
> but it worked poorly. Turned out to be a "depression" where the ball bearing
> sits on bottom plate of points carrier in distributor. There,s a little
> "spring" that locates the ball and because for the last 35 years it had
> wobbled around *in one spot it formed a dent which acted to lock the fixed
> and movable plates of distributor together. *Got a hobby grinder out ,
> ground it away, polished with emery paper. Was just like a new one. If you
> make sure all the items Speedy mentions you can pretty well be sure of a
> cure.
> * * * * *Cheers
> * * * * * *John
>
> "-

rvirgin22 wrote:
> ..
> ..
> John
>
> 1) Absolutely amazing comment. The great value of discussions
> with people who have been driving the same cars for 30 years.
>
> 2) Many would never have thought about the ball-bearing on the
> point plate of the distributor... causing the problem by wearing
> a 30-year-dent/depression into the point plate.
>
> 3) That would certainly prevent the vacuum canister from pulling
> and rotating the point-plate to give that extra timing advance
> required to overcome the acceleration bog, or hesitation, which
> is so irritating in the 050 non-vacuum distributers.
>
> 4) Excellent comment, and cure, John.
>
> 5) And yes, Speedy's recommenations are superb also..... but
> aren't they always. Speedy... and Jan.... and Bob Hoover... and
> others - great members of the Beetle community.
>
> Ross Virgin
> Toronto, Canada
> (where Beetles can drive through 6 feet of snow, and never
> get stuck)

Heh. Not commenting on the carb issue, but I grew up in Toronto, and
drove bugs for many years. Most of the time when there was a big snow, I
was the only one moving. Also the only one scraping my windshield from
the inside, but moving none the less. Regrettably, all my VW's died
before their time due to extreme rust. You ever take your bug to Hayman
Motors for service?

...
...
1) Yes, Hayman Motors for parts - but try to do as much of my own
servicing as possible.

2) Sad to learn of your Beetle loss through rust.

3) One of mine is a 1972 Beetle, driven 35 years in the snow... with
only two little dots of rust. Key is spray... spray... spray...
spray...
the crap out of it with oil. Got 5 Beetles which I srpay 3 or 4 times
a year, at a total cost of about $ 8. The 1972 even still has its
original blue paint job... paint never been touched up, but cleaned,
waxed, then sprayed... and sprayed.......

Ross Virgin
Toronto, Canada
(where Beetles can last forever, even in the snow)
...
...
...
...
> Heh. Not commenting on the carb issue, but I grew up in Toronto, and
> drove bugs for many years. Most of the time when there was a big snow, I
> was the only one moving. Also the only one scraping my windshield from
> the inside, but moving none the less. Regrettably, all my VW's died
> before their time due to extreme rust. You ever take your bug to Hayman
> Motors for service?- Hide quoted text -
>
> - Show quoted text -

rvirgin22 wrote:
> ..
> ..
> 1) Yes, Hayman Motors for parts - but try to do as much of my own
> servicing as possible.
>
Are they still around? To tell you the truth, I stopped driving beetles
when Hayman started ripping me off for service. I really didn't have the
facilities or the time to service my own save for tune ups which were
easy. I took the car to Hayman for brakes and other things. I took my
cars there for close to 10 years.

> 2) Sad to learn of your Beetle loss through rust.

My first, a 1970 beetle literally started dropping pieces of it's self
all over the place. The final straw was when a friend got in the back
and put his foot through the floor.

>
> 3) One of mine is a 1972 Beetle, driven 35 years in the snow... with
> only two little dots of rust. Key is spray... spray... spray...
> spray...
> the crap out of it with oil. Got 5 Beetles which I srpay 3 or 4 times
> a year, at a total cost of about $ 8. The 1972 even still has its
> original blue paint job... paint never been touched up, but cleaned,
> waxed, then sprayed... and sprayed.......
>

I used to get that "rust check" stuff about twice a year but finally my
74 super succumbed to it. Both my bugs were daily drivers and I put a
lot of miles on them. Now, living in Southern California, my 71 super
will last forever :-)


> ..
> ..
> ..
> ..
>> Heh. Not commenting on the carb issue, but I grew up in Toronto, and
>> drove bugs for many years. Most of the time when there was a big snow, I
>> was the only one moving. Also the only one scraping my windshield from
>> the inside, but moving none the less. Regrettably, all my VW's died
>> before their time due to extreme rust. You ever take your bug to Hayman
>> Motors for service?- Hide quoted text -
>>
>> - Show quoted text -
>