VW Golf III with loss of power especially at low RPM

On Mon, 22 Oct 2007 06:00:52 -0500, "dave AKA vwdoc1"
wrote:

>Hmmm 1995 Golf with a 1.8 engine with a carb. Not from the USA AFAIK so my
>responses may not apply.
>
>Does it have a CranK position Sensor?
>Do the instruments lose power like the ign switch was turned off? Maybe ign
>switch?
>Maybe fuel pump relay if so equipped?
>
>good luck!
>--
>later,
>dave
>(One out of many daves)
>
>"Klaus Kragelund" wrote in message
>
>> Hi
>>
>> I have a VW Golf III 1.8 from 1995. My problem is that it suddenly
>> looses power with a very fast jerk and immedeately thereafter resumes
>> power.
>>
>> The problem is worst at low RPM (2000) and it can be solved by giving
>> full pedal. The mechanic has replaced spark plugs, cables, rotor,
>> ignition coil - but the only thing that seems to help is a wonder
>> spray into the carburator
>>
>> My feeling however is that since the problem is RPM dependant, then it
>> can't be the ignitions system - and also since the problem will go
>> away for a while using a spray into the carburator, then the problem
>> must be with the carburator.
>>
>> Do any of you guys have a clue what this is. I have in mind the
>> potentiometers that could be weared out - feeding back a wrong
>> position of a valve.
>>
>> Thanks
>>
>> Klaus Kragelund
>>
>
You do not state what gear you are in when this happens. Is it
possible that the engine is twisting in the engine bay causing an
electrical connector to fail? Loose electrical connections can be hard
to trace. Some of the carb sprays can goof up potentiometers.
 >> Stay informed about: VW Golf III with loss of power especially at low RPM 

In article ,
says...
> I have a VW Golf III 1.8 from 1995. My problem is that it suddenly
> looses power with a very fast jerk and immedeately thereafter resumes
> power.
>
> The problem is worst at low RPM (2000) and it can be solved by giving
> full pedal. The mechanic has replaced spark plugs, cables, rotor,
> ignition coil - but the only thing that seems to help is a wonder
> spray into the carburator

ALL GUESSES, but since it sounds like that may be what your mechanic is
doing too, seems fair. But they could have been reasonable guesses if
those maintenance items were late, so I won't bust on him too hard.

From the 'spray into the carb' comment, sounds like it's also there at
idle?

Could be a vacuum leak or a weak/plugged idle circuit in the carb giving
a lean idle. Once the mains start to come on you feel the surging.

Don't know if there's a mechanical advance on the distributor. Could be
that's sticking up to a certain RPM then they break loose.

If there's a computer, hook it up, read the codes and watch the
indicators. If there's not, put on a timing light and watch the timing
as you go through the symptoms. Tail pipe sniffer might be enlightening
too.

You didn't mention what the old spark plugs looked like. 'Reading the
plugs' is often a helpful clue to what's going on.

If it were me, I'd
- check the hoses for bad spots or not being hooked up
- make sure the air filter is clean
- make sure the choke and carb heat are working properly

Mark
'95 Jetta GLS (USA 2.0l FI gas)
 >> Stay informed about: VW Golf III with loss of power especially at low RPM 

On 22 Okt., 15:19, "SFC" wrote:
> I think he mistakes a monojet injection with a carb. They look very similair
> on the outside......
>
> SFC
>
> "dave AKA vwdoc1" schreef in berichtnews:Fp%Si.221$Yk6.212@nlpi070.nbdc.sbc.com...
>
>

I'm sorry. Yes - I believe it is not a carburator, but just a trottle
to mix gas and air - a monojet.

Regards

Klaus
 >> Stay informed about: VW Golf III with loss of power especially at low RPM 

On 22 Okt., 13:00, "dave AKA vwdoc1" wrote:
> Hmmm 1995 Golf with a 1.8 engine with a carb. Not from the USA AFAIK so my
> responses may not apply.
>
> Does it have a CranK position Sensor?

No idea - I am a electrical engineer and am sorry to say not aware of
all the details.

> Do the instruments lose power like the ign switch was turned off? Maybe ign
> switch?

All instruments functions as normal. I can however hear a relay
tripping, but not nessesarily the same time as the problem. Is
probably another problem. Knock on wood.

> Maybe fuel pump relay if so equipped?
>

Will advice the mechanic

Regards

Klaus
 >> Stay informed about: VW Golf III with loss of power especially at low RPM 

On 22 Okt., 14:09, Jim Behning
wrote:
> On Mon, 22 Oct 2007 06:00:52 -0500, "dave AKA vwdoc1"
>
>
>
>
>
> wrote:
> >Hmmm 1995 Golf with a 1.8 engine with a carb. Not from the USA AFAIK so my
> >responses may not apply.
>
> >Does it have a CranK position Sensor?
> >Do the instruments lose power like the ign switch was turned off? Maybe ign
> >switch?
> >Maybe fuel pump relay if so equipped?
>
> >good luck!
> >--
> >later,
> >dave
> >(One out of many daves)
>
> >"Klaus Kragelund" wrote in message
> >
> >> Hi
>
> >> I have a VW Golf III 1.8 from 1995. My problem is that it suddenly
> >> looses power with a very fast jerk and immedeately thereafter resumes
> >> power.
>
> >> The problem is worst at low RPM (2000) and it can be solved by giving
> >> full pedal. The mechanic has replaced spark plugs, cables, rotor,
> >> ignition coil - but the only thing that seems to help is a wonder
> >> spray into the carburator
>
> >> My feeling however is that since the problem is RPM dependant, then it
> >> can't be the ignitions system - and also since the problem will go
> >> away for a while using a spray into the carburator, then the problem
> >> must be with the carburator.
>
> >> Do any of you guys have a clue what this is. I have in mind the
> >> potentiometers that could be weared out - feeding back a wrong
> >> position of a valve.
>
> >> Thanks
>
> >> Klaus Kragelund
>
> You do not state what gear you are in when this happens. Is it
> possible that the engine is twisting in the engine bay causing an
> electrical connector to fail? Loose electrical connections can be hard
> to trace. Some of the carb sprays can goof up potentiometers.- Skjul tekst i anførselstegn -
>
> - Vis tekst i anførselstegn -

It happens in all gears. My guess is the spray fixes the
potentiometers for a while....

Thanks

Klaus
 >> Stay informed about: VW Golf III with loss of power especially at low RPM 

On 22 Okt., 15:23, Mark Randol wrote:
> In article ,
> says...
>
> > I have a VW Golf III 1.8 from 1995. My problem is that it suddenly
> > looses power with a very fast jerk and immedeately thereafter resumes
> > power.
>
> > The problem is worst at low RPM (2000) and it can be solved by giving
> > full pedal. The mechanic has replaced spark plugs, cables, rotor,
> > ignition coil - but the only thing that seems to help is a wonder
> > spray into the carburator
>
> ALL GUESSES, but since it sounds like that may be what your mechanic is
> doing too, seems fair. But they could have been reasonable guesses if
> those maintenance items were late, so I won't bust on him too hard.
>
> From the 'spray into the carb' comment, sounds like it's also there at
> idle?
>

It is also there at idle. When it happens it is a very sudden loss of
power - like the ignition is removed

> Could be a vacuum leak or a weak/plugged idle circuit in the carb giving
> a lean idle. Once the mains start to come on you feel the surging.
>
> Don't know if there's a mechanical advance on the distributor. Could be
> that's sticking up to a certain RPM then they break loose.
>
> If there's a computer, hook it up, read the codes and watch the
> indicators. If there's not, put on a timing light and watch the timing
> as you go through the symptoms. Tail pipe sniffer might be enlightening
> too.
>
> You didn't mention what the old spark plugs looked like. 'Reading the
> plugs' is often a helpful clue to what's going on.
>

The old plugs were black, and as you say it is therefore not fair to
blame the mechanic all the way.

> If it were me, I'd
> - check the hoses for bad spots or not being hooked up
> - make sure the air filter is clean

New air filter also

> - make sure the choke and carb heat are working properly
>

Thanks, will pass the comments to the mechanic.

Klaus
 >> Stay informed about: VW Golf III with loss of power especially at low RPM 

I think he mistakes a monojet injection with a carb. They look very similair
on the outside......

SFC

"dave AKA vwdoc1" schreef in bericht

> Hmmm 1995 Golf with a 1.8 engine with a carb. Not from the USA AFAIK so
> my responses may not apply.
>
> Does it have a CranK position Sensor?
> Do the instruments lose power like the ign switch was turned off? Maybe
> ign switch?
> Maybe fuel pump relay if so equipped?
>
> good luck!
> --
> later,
> dave
> (One out of many daves)
>
> "Klaus Kragelund" wrote in message
>
>> Hi
>>
>> I have a VW Golf III 1.8 from 1995. My problem is that it suddenly
>> looses power with a very fast jerk and immedeately thereafter resumes
>> power.
>>
>> The problem is worst at low RPM (2000) and it can be solved by giving
>> full pedal. The mechanic has replaced spark plugs, cables, rotor,
>> ignition coil - but the only thing that seems to help is a wonder
>> spray into the carburator
>>
>> My feeling however is that since the problem is RPM dependant, then it
>> can't be the ignitions system - and also since the problem will go
>> away for a while using a spray into the carburator, then the problem
>> must be with the carburator.
>>
>> Do any of you guys have a clue what this is. I have in mind the
>> potentiometers that could be weared out - feeding back a wrong
>> position of a valve.
>>
>> Thanks
>>
>> Klaus Kragelund
>>
>
>
 >> Stay informed about: VW Golf III with loss of power especially at low RPM