My car has gone crazy, and keeps being smarter than me, unwilling to
get fixed. Now engine behaves like dr. Jackal and Hyde.
Problems:
1) COLDMODE: When started cold, car start fine, runs warm on 800-1000.
When it gets warm, idle gradually drops to 200-300, engine nearly
stalls, but mostly catches just in time with flashing dashlights. When
driving, it takes gas badly, and hesitates before engine picks up.
Engine sounds very hollow when idling, also slight loss of power seems
to be present.
2) WARMMODE: When car is started warm, it behaves different. Idle is
oscilating fast between 1000-1200. For the rest it runs fine, and takes
gas very well. Also no loss of power seems to be present.
3) Generally, car runs very rich. I replaced OXS-sensor, but still it
smells on gas, specially when running in COLDMODE. Turning down CO
screw only results in unability to restart at all.

Because i don't like breaking with left foot to keep engine alive when
car has to stop, i removed ISV connector. Without ISV connector, car
shows constant WARMMODE behaviour.

In the last month i changed and cleaned all parts involved in air
intake and fuel injection. Fault code 2121 is present, but new idle
switch didn't make the problems and fault code go away.
Changed parts:
1) Seals of intake pipes.
2) Temp. sensor (black).
3) idle switch.
4) Injector inserts, and o-rings.
5) Plugs/air filter/oil.
6) OXS sensor.
7) Valve conver seal.
Fuel pump is 1 yr. old.
9) Changed cold start Valve, original is suspected to leak or not close
properly.

Question:
I am now at the level where i am desperate. What should i do next ?.
All help is very much appreciated.

 

that code seems to point to throttle switch.
http://www.12v.org/maintenance/dtc.php?code=2121

"2121
Closed Throttle Position Switch. Possible Cause Corrective Steps
a.. Closed Throttle Position (CTP) switch needs adjustment
a.. Throttle valve sticking
a.. Floor mat presses on accelerator pedal
a.. Accelerator pedal cable needs adjustment
a.. Open circuit in wiring to connector A, terminal 9 of ECM
a.. Input for CTP in ECM faulty (ECM is faulty)
a.. Connector A, terminal 9 of ECM has short circuit to ground
a.. Moisture in throttle connector
a.. Check CTP output
a.. Adjust accelerator pedal cable
a.. Repair open/short circuit in wiring

Error is stored if the throttle opening is greater than 7° and the CTP
switch is closed for longer than 1 second, or if the CTP switch has not been
closed at least once as soon as the engine has been started and there has
been a 10 minute drive under 62mph. "

Usually I find that the wires going to the switch break before the plug.
Or the throttle is not fully closing. Does your 100 have a secondary
throttle plate? Possibly it is stiff and does not fully close.

Do you have the Bentley repair manual? If so you can do a multimeter test
from the ECM plug and check out the FI system/sensors/switches.

good luck,
dave



<erikw_nl@yahoo.com> wrote in message
news:1144098889.693334.293680@v46g2000cwv.googlegr oups.com...
> My car has gone crazy, and keeps being smarter than me, unwilling to
> get fixed. Now engine behaves like dr. Jackal and Hyde.
> Problems:
> 1) COLDMODE: When started cold, car start fine, runs warm on 800-1000.
> When it gets warm, idle gradually drops to 200-300, engine nearly
> stalls, but mostly catches just in time with flashing dashlights. When
> driving, it takes gas badly, and hesitates before engine picks up.
> Engine sounds very hollow when idling, also slight loss of power seems
> to be present.
> 2) WARMMODE: When car is started warm, it behaves different. Idle is
> oscilating fast between 1000-1200. For the rest it runs fine, and takes
> gas very well. Also no loss of power seems to be present.
> 3) Generally, car runs very rich. I replaced OXS-sensor, but still it
> smells on gas, specially when running in COLDMODE. Turning down CO
> screw only results in unability to restart at all.
>
> Because i don't like breaking with left foot to keep engine alive when
> car has to stop, i removed ISV connector. Without ISV connector, car
> shows constant WARMMODE behaviour.
>
> In the last month i changed and cleaned all parts involved in air
> intake and fuel injection. Fault code 2121 is present, but new idle
> switch didn't make the problems and fault code go away.
> Changed parts:
> 1) Seals of intake pipes.
> 2) Temp. sensor (black).
> 3) idle switch.
> 4) Injector inserts, and o-rings.
> 5) Plugs/air filter/oil.
> 6) OXS sensor.
> 7) Valve conver seal.
> Fuel pump is 1 yr. old.
> 9) Changed cold start Valve, original is suspected to leak or not close
> properly.
>
> Question:
> I am now at the level where i am desperate. What should i do next ?.
> All help is very much appreciated.
>

 

that code seems to point to throttle switch.
http://www.12v.org/maintenance/dtc.php?code=2121

"2121
Closed Throttle Position Switch. Possible Cause Corrective Steps
a.. Closed Throttle Position (CTP) switch needs adjustment
a.. Throttle valve sticking
a.. Floor mat presses on accelerator pedal
a.. Accelerator pedal cable needs adjustment
a.. Open circuit in wiring to connector A, terminal 9 of ECM
a.. Input for CTP in ECM faulty (ECM is faulty)
a.. Connector A, terminal 9 of ECM has short circuit to ground
a.. Moisture in throttle connector
a.. Check CTP output
a.. Adjust accelerator pedal cable
a.. Repair open/short circuit in wiring

Error is stored if the throttle opening is greater than 7° and the CTP
switch is closed for longer than 1 second, or if the CTP switch has not been
closed at least once as soon as the engine has been started and there has
been a 10 minute drive under 62mph. "

Usually I find that the wires going to the switch break before the plug.
Or the throttle is not fully closing. Does your 100 have a secondary
throttle plate? Possibly it is stiff and does not fully close.

Do you have the Bentley repair manual? If so you can do a multimeter test
from the ECM plug and check out the FI system/sensors/switches.

good luck,
dave



<erikw_nl@yahoo.com> wrote in message
news:1144098889.693334.293680@v46g2000cwv.googlegr oups.com...
> My car has gone crazy, and keeps being smarter than me, unwilling to
> get fixed. Now engine behaves like dr. Jackal and Hyde.
> Problems:
> 1) COLDMODE: When started cold, car start fine, runs warm on 800-1000.
> When it gets warm, idle gradually drops to 200-300, engine nearly
> stalls, but mostly catches just in time with flashing dashlights. When
> driving, it takes gas badly, and hesitates before engine picks up.
> Engine sounds very hollow when idling, also slight loss of power seems
> to be present.
> 2) WARMMODE: When car is started warm, it behaves different. Idle is
> oscilating fast between 1000-1200. For the rest it runs fine, and takes
> gas very well. Also no loss of power seems to be present.
> 3) Generally, car runs very rich. I replaced OXS-sensor, but still it
> smells on gas, specially when running in COLDMODE. Turning down CO
> screw only results in unability to restart at all.
>
> Because i don't like breaking with left foot to keep engine alive when
> car has to stop, i removed ISV connector. Without ISV connector, car
> shows constant WARMMODE behaviour.
>
> In the last month i changed and cleaned all parts involved in air
> intake and fuel injection. Fault code 2121 is present, but new idle
> switch didn't make the problems and fault code go away.
> Changed parts:
> 1) Seals of intake pipes.
> 2) Temp. sensor (black).
> 3) idle switch.
> 4) Injector inserts, and o-rings.
> 5) Plugs/air filter/oil.
> 6) OXS sensor.
> 7) Valve conver seal.
> Fuel pump is 1 yr. old.
> 9) Changed cold start Valve, original is suspected to leak or not close
> properly.
>
> Question:
> I am now at the level where i am desperate. What should i do next ?.
> All help is very much appreciated.
>

 

that code seems to point to throttle switch.
http://www.12v.org/maintenance/dtc.php?code=2121

"2121
Closed Throttle Position Switch. Possible Cause Corrective Steps
a.. Closed Throttle Position (CTP) switch needs adjustment
a.. Throttle valve sticking
a.. Floor mat presses on accelerator pedal
a.. Accelerator pedal cable needs adjustment
a.. Open circuit in wiring to connector A, terminal 9 of ECM
a.. Input for CTP in ECM faulty (ECM is faulty)
a.. Connector A, terminal 9 of ECM has short circuit to ground
a.. Moisture in throttle connector
a.. Check CTP output
a.. Adjust accelerator pedal cable
a.. Repair open/short circuit in wiring

Error is stored if the throttle opening is greater than 7° and the CTP
switch is closed for longer than 1 second, or if the CTP switch has not been
closed at least once as soon as the engine has been started and there has
been a 10 minute drive under 62mph. "

Usually I find that the wires going to the switch break before the plug.
Or the throttle is not fully closing. Does your 100 have a secondary
throttle plate? Possibly it is stiff and does not fully close.

Do you have the Bentley repair manual? If so you can do a multimeter test
from the ECM plug and check out the FI system/sensors/switches.

good luck,
dave



<erikw_nl@yahoo.com> wrote in message
news:1144098889.693334.293680@v46g2000cwv.googlegr oups.com...
> My car has gone crazy, and keeps being smarter than me, unwilling to
> get fixed. Now engine behaves like dr. Jackal and Hyde.
> Problems:
> 1) COLDMODE: When started cold, car start fine, runs warm on 800-1000.
> When it gets warm, idle gradually drops to 200-300, engine nearly
> stalls, but mostly catches just in time with flashing dashlights. When
> driving, it takes gas badly, and hesitates before engine picks up.
> Engine sounds very hollow when idling, also slight loss of power seems
> to be present.
> 2) WARMMODE: When car is started warm, it behaves different. Idle is
> oscilating fast between 1000-1200. For the rest it runs fine, and takes
> gas very well. Also no loss of power seems to be present.
> 3) Generally, car runs very rich. I replaced OXS-sensor, but still it
> smells on gas, specially when running in COLDMODE. Turning down CO
> screw only results in unability to restart at all.
>
> Because i don't like breaking with left foot to keep engine alive when
> car has to stop, i removed ISV connector. Without ISV connector, car
> shows constant WARMMODE behaviour.
>
> In the last month i changed and cleaned all parts involved in air
> intake and fuel injection. Fault code 2121 is present, but new idle
> switch didn't make the problems and fault code go away.
> Changed parts:
> 1) Seals of intake pipes.
> 2) Temp. sensor (black).
> 3) idle switch.
> 4) Injector inserts, and o-rings.
> 5) Plugs/air filter/oil.
> 6) OXS sensor.
> 7) Valve conver seal.
> Fuel pump is 1 yr. old.
> 9) Changed cold start Valve, original is suspected to leak or not close
> properly.
>
> Question:
> I am now at the level where i am desperate. What should i do next ?.
> All help is very much appreciated.
>

 

Hi dave,

> Usually I find that the wires going to the switch break before the plug.
> Or the throttle is not fully closing. Does your 100 have a secondary
> throttle plate? Possibly it is stiff and does not fully close.
You ask if throttle does not close well and let pass air into engine
although it should be closed ?.

I checked throttle body. connected multimeter to terminals 1-2 of
connector, and as soon the throttle is moved little, switch opens. Same
holds for full-throttle switch. On the plug ends there is 12V.

>
> Do you have the Bentley repair manual? If so you can do a multimeter test
> from the ECM plug and check out the FI system/sensors/switches.
>
I have Bentley manual, and tested cables from ecm plug to terminal,
will check again if there is a ground-leak or short.

You have a clue why engine is running in two modes when ISV is
connected ?. Sometimes it looks as if ISV tries to regulate engine
speeds, but can not hold it because something is out of spec.


> good luck,
> dave
Thx very much again.
>
>

 

Hi dave,

> Usually I find that the wires going to the switch break before the plug.
> Or the throttle is not fully closing. Does your 100 have a secondary
> throttle plate? Possibly it is stiff and does not fully close.
You ask if throttle does not close well and let pass air into engine
although it should be closed ?.

I checked throttle body. connected multimeter to terminals 1-2 of
connector, and as soon the throttle is moved little, switch opens. Same
holds for full-throttle switch. On the plug ends there is 12V.

>
> Do you have the Bentley repair manual? If so you can do a multimeter test
> from the ECM plug and check out the FI system/sensors/switches.
>
I have Bentley manual, and tested cables from ecm plug to terminal,
will check again if there is a ground-leak or short.

You have a clue why engine is running in two modes when ISV is
connected ?. Sometimes it looks as if ISV tries to regulate engine
speeds, but can not hold it because something is out of spec.


> good luck,
> dave
Thx very much again.
>
>

 

Hi dave,

> Usually I find that the wires going to the switch break before the plug.
> Or the throttle is not fully closing. Does your 100 have a secondary
> throttle plate? Possibly it is stiff and does not fully close.
You ask if throttle does not close well and let pass air into engine
although it should be closed ?.

I checked throttle body. connected multimeter to terminals 1-2 of
connector, and as soon the throttle is moved little, switch opens. Same
holds for full-throttle switch. On the plug ends there is 12V.

>
> Do you have the Bentley repair manual? If so you can do a multimeter test
> from the ECM plug and check out the FI system/sensors/switches.
>
I have Bentley manual, and tested cables from ecm plug to terminal,
will check again if there is a ground-leak or short.

You have a clue why engine is running in two modes when ISV is
connected ?. Sometimes it looks as if ISV tries to regulate engine
speeds, but can not hold it because something is out of spec.


> good luck,
> dave
Thx very much again.
>
>

 

REPLIES WITHIN

<erikw_nl@yahoo.com> wrote in message
news:1144180375.835177.32730@i40g2000cwc.googlegro ups.com...
> Hi dave,
>
>> Usually I find that the wires going to the switch break before the plug.
>> Or the throttle is not fully closing. Does your 100 have a secondary
>> throttle plate? Possibly it is stiff and does not fully close.
> You ask if throttle does not close well and let pass air into engine
> although it should be closed ?.
>
> I checked throttle body. connected multimeter to terminals 1-2 of
> connector, and as soon the throttle is moved little, switch opens. Same
> holds for full-throttle switch. On the plug ends there is 12V.

But if there is a secondary butterfly valve, that 2nd valve could be staying
open just a hair creating a problem like you are describing.
Sounds like things are good there electrically.

>
>>
>> Do you have the Bentley repair manual? If so you can do a multimeter
>> test
>> from the ECM plug and check out the FI system/sensors/switches.
>>
> I have Bentley manual, and tested cables from ecm plug to terminal,
> will check again if there is a ground-leak or short.
>
> You have a clue why engine is running in two modes when ISV is
> connected ?. Sometimes it looks as if ISV tries to regulate engine
> speeds, but can not hold it because something is out of spec.

That is why checking from the ECM plug is a good way to find/test out the
system electrically.
Don't forget that mechanical things can create problems like the throttle
body plates, fuel distributor and boot, etc.
Does EVERYTHING check out within specs? How is the coolant temperature
sensor?
How is the fuel pressure? Too much, too little or just right?

That code is pointing you to the throttle body though!!
What year is this Audi?

thinking out loud!
--
later,
dave
(One out of many daves)

 

REPLIES WITHIN

<erikw_nl@yahoo.com> wrote in message
news:1144180375.835177.32730@i40g2000cwc.googlegro ups.com...
> Hi dave,
>
>> Usually I find that the wires going to the switch break before the plug.
>> Or the throttle is not fully closing. Does your 100 have a secondary
>> throttle plate? Possibly it is stiff and does not fully close.
> You ask if throttle does not close well and let pass air into engine
> although it should be closed ?.
>
> I checked throttle body. connected multimeter to terminals 1-2 of
> connector, and as soon the throttle is moved little, switch opens. Same
> holds for full-throttle switch. On the plug ends there is 12V.

But if there is a secondary butterfly valve, that 2nd valve could be staying
open just a hair creating a problem like you are describing.
Sounds like things are good there electrically.

>
>>
>> Do you have the Bentley repair manual? If so you can do a multimeter
>> test
>> from the ECM plug and check out the FI system/sensors/switches.
>>
> I have Bentley manual, and tested cables from ecm plug to terminal,
> will check again if there is a ground-leak or short.
>
> You have a clue why engine is running in two modes when ISV is
> connected ?. Sometimes it looks as if ISV tries to regulate engine
> speeds, but can not hold it because something is out of spec.

That is why checking from the ECM plug is a good way to find/test out the
system electrically.
Don't forget that mechanical things can create problems like the throttle
body plates, fuel distributor and boot, etc.
Does EVERYTHING check out within specs? How is the coolant temperature
sensor?
How is the fuel pressure? Too much, too little or just right?

That code is pointing you to the throttle body though!!
What year is this Audi?

thinking out loud!
--
later,
dave
(One out of many daves)

 

REPLIES WITHIN

<erikw_nl@yahoo.com> wrote in message
news:1144180375.835177.32730@i40g2000cwc.googlegro ups.com...
> Hi dave,
>
>> Usually I find that the wires going to the switch break before the plug.
>> Or the throttle is not fully closing. Does your 100 have a secondary
>> throttle plate? Possibly it is stiff and does not fully close.
> You ask if throttle does not close well and let pass air into engine
> although it should be closed ?.
>
> I checked throttle body. connected multimeter to terminals 1-2 of
> connector, and as soon the throttle is moved little, switch opens. Same
> holds for full-throttle switch. On the plug ends there is 12V.

But if there is a secondary butterfly valve, that 2nd valve could be staying
open just a hair creating a problem like you are describing.
Sounds like things are good there electrically.

>
>>
>> Do you have the Bentley repair manual? If so you can do a multimeter
>> test
>> from the ECM plug and check out the FI system/sensors/switches.
>>
> I have Bentley manual, and tested cables from ecm plug to terminal,
> will check again if there is a ground-leak or short.
>
> You have a clue why engine is running in two modes when ISV is
> connected ?. Sometimes it looks as if ISV tries to regulate engine
> speeds, but can not hold it because something is out of spec.

That is why checking from the ECM plug is a good way to find/test out the
system electrically.
Don't forget that mechanical things can create problems like the throttle
body plates, fuel distributor and boot, etc.
Does EVERYTHING check out within specs? How is the coolant temperature
sensor?
How is the fuel pressure? Too much, too little or just right?

That code is pointing you to the throttle body though!!
What year is this Audi?

thinking out loud!
--
later,
dave
(One out of many daves)