VN idle problem

[Ext User(TJB)]

The old VN has been running very well but lately has trouble with the idle.
When you come to a stop, auto still in drive, i.e. at traffic lights, the
idle drops to about the normal level, just over half way on the dash tacho
between 0 and 1000 rpm. (Unfortunately I only have an old rpm meter and I
am not sure how I would connect it to the VN for a more accurate reading).
However after a short while the idle speed starts to slowly decrease to
just above the 0 on the tacho, where its start to vibrate more than usual.
So far it has not actually konked out, just idles very low.

The engine light flashes the usual 12. I have only checked then IAC by
simply unpluging it and seeing the rpm go very high at start and back to
normal when plugged back it. I have also disconnected the battery and run
the engne at >3000 rpm for 10 seconds. Unfortunately with lpg it's a pain
to remove the throttle body to measure IAC resistance. Leads are new (and
okay), as are the spark plugs.

Anything else I should try or do? If I do remove the throttle anything to
watch out for in cleaning/checking it??



Thanks
TJB

[Ext User(TJB)]

TJB <2lazyToGet@one> wrote in news:Xns9A0DCFB14306IDWhatID@216.168.3.72:

> The old VN has been running very well but lately has trouble with the
> idle. When you come to a stop, auto still in drive, i.e. at traffic
> lights, the idle drops to about the normal level, just over half way
> on the dash tacho between 0 and 1000 rpm. (Unfortunately I only have
> an old rpm meter and I am not sure how I would connect it to the VN
> for a more accurate reading). However after a short while the idle
> speed starts to slowly decrease to just above the 0 on the tacho,
> where its start to vibrate more than usual. So far it has not actually
> konked out, just idles very low.
>
> The engine light flashes the usual 12. I have only checked then IAC by
> simply unpluging it and seeing the rpm go very high at start and back
> to normal when plugged back it. I have also disconnected the battery
> and run the engne at >3000 rpm for 10 seconds. Unfortunately with lpg
> it's a pain to remove the throttle body to measure IAC resistance.
> Leads are new (and okay), as are the spark plugs.
>
> Anything else I should try or do? If I do remove the throttle
> anything to watch out for in cleaning/checking it??
>
>
>
> Thanks
> TJB
>

I should point out that the engine doesn't idle rough (for a VN that is)
its just that it start to idle at the right speed and about a minute later
the idle starts to slowly decrease in rpms to something quite low.

TJB

[Ext User(Klompmeester)]

"TJB" <2lazyToGet@one> wrote in message
news:Xns9A0DCFB14306IDWhatID@216.168.3.72...
> The old VN has been running very well but lately has trouble with the
> idle.
> When you come to a stop, auto still in drive, i.e. at traffic lights, the
> idle drops to about the normal level, just over half way on the dash tacho
> between 0 and 1000 rpm. (Unfortunately I only have an old rpm meter and I
> am not sure how I would connect it to the VN for a more accurate reading).
> However after a short while the idle speed starts to slowly decrease to
> just above the 0 on the tacho, where its start to vibrate more than usual.
> So far it has not actually konked out, just idles very low.
>
> The engine light flashes the usual 12. I have only checked then IAC by
> simply unpluging it and seeing the rpm go very high at start and back to
> normal when plugged back it. I have also disconnected the battery and run
> the engne at >3000 rpm for 10 seconds. Unfortunately with lpg it's a pain
> to remove the throttle body to measure IAC resistance. Leads are new (and
> okay), as are the spark plugs.
>
> Anything else I should try or do? If I do remove the throttle anything to
> watch out for in cleaning/checking it??
>
Clean the throttle body including removal of the IAC for gentle pintle
cleaning and check all vacuum hoses are connected and in sound condition.
Check base idle by putting the ECU into service mode and adjusting it to
400rpm. You can only do this after cleaning the throttle body.

You then have to do a relearn procedure as outlined below;

Pull the engine/efi fuse for 30 seconds and then put it back in.

Start the engine and keep it running at 1500rpm whilsts the IAC is being
reset by the ECM for about 15 seconds, then, with foot on brake the whole
time...

30 seconds in Park, A/C off
30 seconds in Drive, A/C off
30 seconds in Park, A/C on
30 seconds in Drive, A/C on

That completes the relearn and the idle should be markedly improved
thoughout.

For a short term fix you can just do the relearn procedure as outlined above
skipping the cleaning and see if that improves things.

[Ext User(Klompmeester)]

"TJB" <2lazyToGet@one> wrote in message
news:Xns9A0DD8543BA6FIDWhatID@216.168.3.72...
> TJB <2lazyToGet@one> wrote in news:Xns9A0DCFB14306IDWhatID@216.168.3.72:
>
>> The old VN has been running very well but lately has trouble with the
>> idle. When you come to a stop, auto still in drive, i.e. at traffic
>> lights, the idle drops to about the normal level, just over half way
>> on the dash tacho between 0 and 1000 rpm. (Unfortunately I only have
>> an old rpm meter and I am not sure how I would connect it to the VN
>> for a more accurate reading). However after a short while the idle
>> speed starts to slowly decrease to just above the 0 on the tacho,
>> where its start to vibrate more than usual. So far it has not actually
>> konked out, just idles very low.
>>
>> The engine light flashes the usual 12. I have only checked then IAC by
>> simply unpluging it and seeing the rpm go very high at start and back
>> to normal when plugged back it. I have also disconnected the battery
>> and run the engne at >3000 rpm for 10 seconds. Unfortunately with lpg
>> it's a pain to remove the throttle body to measure IAC resistance.
>> Leads are new (and okay), as are the spark plugs.
>>
>> Anything else I should try or do? If I do remove the throttle
>> anything to watch out for in cleaning/checking it??
>>

See my other reply, but don't disturb the base idle screw or TPS unless you
know how to set them up again.

When you have thoroughly cleaned the throttle body, spray a bit of CRC on
the throttle shafts inside the throttle body and allow it to penetrate down
into the housing (gravity feeding works best). Make sure the seal for the
IAC is intact and clean.

[Ext User(TJB)]

"Klompmeester" <whowhere@andwhy.com> wrote in
news:13mo9qqbtkn1u02@corp.supernews.com:

>
> "TJB" <2lazyToGet@one> wrote in message
> news:Xns9A0DCFB14306IDWhatID@216.168.3.72...
>> The old VN has been running very well but lately has trouble with the
>> idle.
>> When you come to a stop, auto still in drive, i.e. at traffic lights,
>> the idle drops to about the normal level, just over half way on the
>> dash tacho between 0 and 1000 rpm. (Unfortunately I only have an old
>> rpm meter and I am not sure how I would connect it to the VN for a
>> more accurate reading). However after a short while the idle speed
>> starts to slowly decrease to just above the 0 on the tacho, where its
>> start to vibrate more than usual. So far it has not actually konked
>> out, just idles very low.
>>
>> The engine light flashes the usual 12. I have only checked then IAC
>> by simply unpluging it and seeing the rpm go very high at start and
>> back to normal when plugged back it. I have also disconnected the
>> battery and run the engne at >3000 rpm for 10 seconds. Unfortunately
>> with lpg it's a pain to remove the throttle body to measure IAC
>> resistance. Leads are new (and okay), as are the spark plugs.
>>
>> Anything else I should try or do? If I do remove the throttle
>> anything to watch out for in cleaning/checking it??
>>
> Clean the throttle body including removal of the IAC for gentle pintle
> cleaning and check all vacuum hoses are connected and in sound
> condition. Check base idle by putting the ECU into service mode and
> adjusting it to 400rpm. You can only do this after cleaning the
> throttle body.
>
> You then have to do a relearn procedure as outlined below;
>
> Pull the engine/efi fuse for 30 seconds and then put it back in.
>
> Start the engine and keep it running at 1500rpm whilsts the IAC is
> being reset by the ECM for about 15 seconds, then, with foot on brake
> the whole time...
>
> 30 seconds in Park, A/C off
> 30 seconds in Drive, A/C off
> 30 seconds in Park, A/C on
> 30 seconds in Drive, A/C on
>
> That completes the relearn and the idle should be markedly improved
> thoughout.
>
> For a short term fix you can just do the relearn procedure as outlined
> above skipping the cleaning and see if that improves things.
>
>
>
>


Thanks alot guys I will try the relearn first and do the clean after
Chrstmas if it still requires it, however I am not sure how I can read
400 rpm as I only have an older Dwell/Tachometer.

Cheers
TJB

[Ext User(Klompmeester)]

"TJB" <2lazyToGet@one> wrote in message
news:Xns9A0E5F7BF4D13IDWhatID@216.168.3.72...
> "Klompmeester" <whowhere@andwhy.com> wrote in
> news:13mo9qqbtkn1u02@corp.supernews.com:
>
>>
>> "TJB" <2lazyToGet@one> wrote in message
>> news:Xns9A0DCFB14306IDWhatID@216.168.3.72...
>>> The old VN has been running very well but lately has trouble with the
>>> idle.
>>> When you come to a stop, auto still in drive, i.e. at traffic lights,
>>> the idle drops to about the normal level, just over half way on the
>>> dash tacho between 0 and 1000 rpm. (Unfortunately I only have an old
>>> rpm meter and I am not sure how I would connect it to the VN for a
>>> more accurate reading). However after a short while the idle speed
>>> starts to slowly decrease to just above the 0 on the tacho, where its
>>> start to vibrate more than usual. So far it has not actually konked
>>> out, just idles very low.
>>>
>>> The engine light flashes the usual 12. I have only checked then IAC
>>> by simply unpluging it and seeing the rpm go very high at start and
>>> back to normal when plugged back it. I have also disconnected the
>>> battery and run the engne at >3000 rpm for 10 seconds. Unfortunately
>>> with lpg it's a pain to remove the throttle body to measure IAC
>>> resistance. Leads are new (and okay), as are the spark plugs.
>>>
>>> Anything else I should try or do? If I do remove the throttle
>>> anything to watch out for in cleaning/checking it??
>>>
>> Clean the throttle body including removal of the IAC for gentle pintle
>> cleaning and check all vacuum hoses are connected and in sound
>> condition. Check base idle by putting the ECU into service mode and
>> adjusting it to 400rpm. You can only do this after cleaning the
>> throttle body.
>>
>> You then have to do a relearn procedure as outlined below;
>>
>> Pull the engine/efi fuse for 30 seconds and then put it back in.
>>
>> Start the engine and keep it running at 1500rpm whilsts the IAC is
>> being reset by the ECM for about 15 seconds, then, with foot on brake
>> the whole time...
>>
>> 30 seconds in Park, A/C off
>> 30 seconds in Drive, A/C off
>> 30 seconds in Park, A/C on
>> 30 seconds in Drive, A/C on
>>
>> That completes the relearn and the idle should be markedly improved
>> thoughout.
>>
>> For a short term fix you can just do the relearn procedure as outlined
>> above skipping the cleaning and see if that improves things.
>>
>>
>>
>>
>
>
> Thanks alot guys I will try the relearn first and do the clean after
> Chrstmas if it still requires it, however I am not sure how I can read
> 400 rpm as I only have an older Dwell/Tachometer.

There is a connector for the tacho near the top of the guard from memory
passenger side of the car. It's a single terminal connector that you can
connect to a tacho.
You need to short two terminals on the DLC connector to put the ECU into
service mode. I can look it up if you need to know which two terminals they
are.

[Ext User(TJB)]

TJB <2lazyToGet@one> wrote in
news:Xns9A0E5F7BF4D13IDWhatID@216.168.3.72:

> "Klompmeester" <whowhere@andwhy.com> wrote in
> news:13mo9qqbtkn1u02@corp.supernews.com:
>
>>
>> "TJB" <2lazyToGet@one> wrote in message
>> news:Xns9A0DCFB14306IDWhatID@216.168.3.72...
>>> The old VN .......
>>>
>>>
>>>
>> Clean the throttle body including removal of the IAC for gentle
>> pintle cleaning and check all vacuum hoses are connected and in sound
>> condition. Check base idle by putting the ECU into service mode and
>> adjusting it to 400rpm. You can only do this after cleaning the
>> throttle body.
>>
>> You then have to do a relearn procedure as outlined below;
>>
>> Pull the engine/efi fuse for 30 seconds and then put it back in.
>>
>> Start the engine and keep it running at 1500rpm whilsts the IAC is
>> being reset by the ECM for about 15 seconds, then, with foot on brake
>> the whole time...
>>
>> 30 seconds in Park, A/C off
>> 30 seconds in Drive, A/C off
>> 30 seconds in Park, A/C on
>> 30 seconds in Drive, A/C on
>>
>> That completes the relearn and the idle should be markedly improved
>> thoughout.
>>
>> For a short term fix you can just do the relearn procedure as
>> outlined above skipping the cleaning and see if that improves things.
>>
>>
>>
>>
>
>
> Thanks alot guys I will try the relearn first and do the clean after
> Chrstmas if it still requires it, however I am not sure how I can read
> 400 rpm as I only have an older Dwell/Tachometer.
>
> Cheers
> TJB
>

Unfortunately the simple reset didn't improve anything so it looks like
a clean job.

Cheers
TJB

[Ext User(TJB)]

TJB <2lazyToGet@one> wrote in
news:Xns9A0E6F03CF51EIDWhatID@216.168.3.72:

> TJB <2lazyToGet@one> wrote in
> news:Xns9A0E5F7BF4D13IDWhatID@216.168.3.72:
>
>> "Klompmeester" <whowhere@andwhy.com> wrote in
>> news:13mo9qqbtkn1u02@corp.supernews.com:
>>
>>>
>>> "TJB" <2lazyToGet@one> wrote in message
>>> news:Xns9A0DCFB14306IDWhatID@216.168.3.72...
>>>> The old VN .......
>>>>
>>>>
>>>>
>>> Clean the throttle body including removal of the IAC for gentle
>>> pintle cleaning and check all vacuum hoses are connected and in
>>> sound condition. Check base idle by putting the ECU into service
>>> mode and adjusting it to 400rpm. You can only do this after cleaning
>>> the throttle body.
>>>
>>> You then have to do a relearn procedure as outlined below;
>>>
>>> Pull the engine/efi fuse for 30 seconds and then put it back in.
>>>
>>> Start the engine and keep it running at 1500rpm whilsts the IAC is
>>> being reset by the ECM for about 15 seconds, then, with foot on
>>> brake the whole time...
>>>
>>> 30 seconds in Park, A/C off
>>> 30 seconds in Drive, A/C off
>>> 30 seconds in Park, A/C on
>>> 30 seconds in Drive, A/C on
>>>
>>> That completes the relearn and the idle should be markedly improved
>>> thoughout.
>>>
>>> For a short term fix you can just do the relearn procedure as
>>> outlined above skipping the cleaning and see if that improves
>>> things.
>>>
>>>
>>>
>>>
>>
>>
>> Thanks alot guys I will try the relearn first and do the clean after
>> Chrstmas if it still requires it, however I am not sure how I can
>> read 400 rpm as I only have an older Dwell/Tachometer.
>>
>> Cheers
>> TJB
>>
>
> Unfortunately the simple reset didn't improve anything so it looks
> like a clean job.
>
> Cheers
> TJB
>

I also assume you still have to do a 3000rpm/10sec to reset the MAP??

TJB

[Ext User(TJB)]

"Klompmeester" <whowhere@andwhy.com> wrote in
news:13mokm06tvrgk1f@corp.supernews.com:

>
> "TJB" <2lazyToGet@one> wrote in message
> news:Xns9A0E5F7BF4D13IDWhatID@216.168.3.72...
>> "Klompmeester" <whowhere@andwhy.com> wrote in
>> news:13mo9qqbtkn1u02@corp.supernews.com:
>>
>>>
>>> "TJB" <2lazyToGet@one> wrote in message
>>> news:Xns9A0DCFB14306IDWhatID@216.168.3.72...
>>>> The old VN has been running very well but lately has trouble with
>>>> the idle.
>>>> When you come to a stop, auto still in drive, i.e. at traffic
>>>> lights, the idle drops to about the normal level, just over half
>>>> way on the dash tacho between 0 and 1000 rpm. (Unfortunately I only
>>>> have an old rpm meter and I am not sure how I would connect it to
>>>> the VN for a more accurate reading). However after a short while
>>>> the idle speed starts to slowly decrease to just above the 0 on the
>>>> tacho, where its start to vibrate more than usual. So far it has
>>>> not actually konked out, just idles very low.
>>>>
>>>> The engine light flashes the usual 12. I have only checked then IAC
>>>> by simply unpluging it and seeing the rpm go very high at start and
>>>> back to normal when plugged back it. I have also disconnected the
>>>> battery and run the engne at >3000 rpm for 10 seconds.
>>>> Unfortunately with lpg it's a pain to remove the throttle body to
>>>> measure IAC resistance. Leads are new (and okay), as are the spark
>>>> plugs.
>>>>
>>>> Anything else I should try or do? If I do remove the throttle
>>>> anything to watch out for in cleaning/checking it??
>>>>
>>> Clean the throttle body including removal of the IAC for gentle
>>> pintle cleaning and check all vacuum hoses are connected and in
>>> sound condition. Check base idle by putting the ECU into service
>>> mode and adjusting it to 400rpm. You can only do this after cleaning
>>> the throttle body.
>>>
>>> You then have to do a relearn procedure as outlined below;
>>>
>>> Pull the engine/efi fuse for 30 seconds and then put it back in.
>>>
>>> Start the engine and keep it running at 1500rpm whilsts the IAC is
>>> being reset by the ECM for about 15 seconds, then, with foot on
>>> brake the whole time...
>>>
>>> 30 seconds in Park, A/C off
>>> 30 seconds in Drive, A/C off
>>> 30 seconds in Park, A/C on
>>> 30 seconds in Drive, A/C on
>>>
>>> That completes the relearn and the idle should be markedly improved
>>> thoughout.
>>>
>>> For a short term fix you can just do the relearn procedure as
>>> outlined above skipping the cleaning and see if that improves
>>> things.
>>>
>>>
>>>
>>>
>>
>>
>> Thanks alot guys I will try the relearn first and do the clean after
>> Chrstmas if it still requires it, however I am not sure how I can
>> read 400 rpm as I only have an older Dwell/Tachometer.
>
> There is a connector for the tacho near the top of the guard from
> memory passenger side of the car. It's a single terminal connector
> that you can connect to a tacho.
> You need to short two terminals on the DLC connector to put the ECU
> into service mode. I can look it up if you need to know which two
> terminals they are.
>
>
>
>

If you can let me know the two terminals that would be great, I only
have info regarding diagnostic mode. Also I have just cleaned the IAC
and some how, it seems to be too long to go back in, measured about
37mm??? I gently pushed it back in, in a side to side motion until it
fitted. Is there any problems in doing that or have I just damaged it?


Thanks
TJB

[Ext User(mmal380vrx@hotmail.com)]

On Dec 21, 8:52 pm, TJB <2lazyToGet@one> wrote:
> The old VN has been running very well but lately has trouble with the idle.
> When you come to a stop, auto still in drive, i.e. at traffic lights, the
> idle drops to about the normal level, just over half way on the dash tacho
> between 0 and 1000 rpm. (Unfortunately I only have an old rpm meter and I
> am not sure how I would connect it to the VN for a more accurate reading).
> However after a short while the idle speed starts to slowly decrease to
> just above the 0 on the tacho, where its start to vibrate more than usual.
> So far it has not actually konked out, just idles very low.
>
> The engine light flashes the usual 12. I have only checked then IAC by
> simply unpluging it and seeing the rpm go very high at start and back to
> normal when plugged back it. I have also disconnected the battery and run
> the engne at >3000 rpm for 10 seconds. Unfortunately with lpg it's a pain
> to remove the throttle body to measure IAC resistance. Leads are new (and
> okay), as are the spark plugs.
>
> Anything else I should try or do? If I do remove the throttle anything to
> watch out for in cleaning/checking it??
>
> Thanks
> TJB

hahahaha its a holden you can expect more problems than just the idle
trade it up for a magna instead because they are trouble free cars

[Ext User(Klompmeester)]

"TJB" <2lazyToGet@one> wrote in message
news:Xns9A0E89E32F23EIDWhatID@216.168.3.72...
> "Klompmeester" <whowhere@andwhy.com> wrote in
> news:13mokm06tvrgk1f@corp.supernews.com:
>
>>
>> "TJB" <2lazyToGet@one> wrote in message
>> news:Xns9A0E5F7BF4D13IDWhatID@216.168.3.72...
>>> "Klompmeester" <whowhere@andwhy.com> wrote in
>>> news:13mo9qqbtkn1u02@corp.supernews.com:
>>>
>>>>
>>>> "TJB" <2lazyToGet@one> wrote in message
>>>> news:Xns9A0DCFB14306IDWhatID@216.168.3.72...
>>>>> The old VN has been running very well but lately has trouble with
>>>>> the idle.
>>>>> When you come to a stop, auto still in drive, i.e. at traffic
>>>>> lights, the idle drops to about the normal level, just over half
>>>>> way on the dash tacho between 0 and 1000 rpm. (Unfortunately I only
>>>>> have an old rpm meter and I am not sure how I would connect it to
>>>>> the VN for a more accurate reading). However after a short while
>>>>> the idle speed starts to slowly decrease to just above the 0 on the
>>>>> tacho, where its start to vibrate more than usual. So far it has
>>>>> not actually konked out, just idles very low.
>>>>>
>>>>> The engine light flashes the usual 12. I have only checked then IAC
>>>>> by simply unpluging it and seeing the rpm go very high at start and
>>>>> back to normal when plugged back it. I have also disconnected the
>>>>> battery and run the engne at >3000 rpm for 10 seconds.
>>>>> Unfortunately with lpg it's a pain to remove the throttle body to
>>>>> measure IAC resistance. Leads are new (and okay), as are the spark
>>>>> plugs.
>>>>>
>>>>> Anything else I should try or do? If I do remove the throttle
>>>>> anything to watch out for in cleaning/checking it??
>>>>>
>>>> Clean the throttle body including removal of the IAC for gentle
>>>> pintle cleaning and check all vacuum hoses are connected and in
>>>> sound condition. Check base idle by putting the ECU into service
>>>> mode and adjusting it to 400rpm. You can only do this after cleaning
>>>> the throttle body.
>>>>
>>>> You then have to do a relearn procedure as outlined below;
>>>>
>>>> Pull the engine/efi fuse for 30 seconds and then put it back in.
>>>>
>>>> Start the engine and keep it running at 1500rpm whilsts the IAC is
>>>> being reset by the ECM for about 15 seconds, then, with foot on
>>>> brake the whole time...
>>>>
>>>> 30 seconds in Park, A/C off
>>>> 30 seconds in Drive, A/C off
>>>> 30 seconds in Park, A/C on
>>>> 30 seconds in Drive, A/C on
>>>>
>>>> That completes the relearn and the idle should be markedly improved
>>>> thoughout.
>>>>
>>>> For a short term fix you can just do the relearn procedure as
>>>> outlined above skipping the cleaning and see if that improves
>>>> things.
>>>>
>>>>
>>>>
>>>>
>>>
>>>
>>> Thanks alot guys I will try the relearn first and do the clean after
>>> Chrstmas if it still requires it, however I am not sure how I can
>>> read 400 rpm as I only have an older Dwell/Tachometer.
>>
>> There is a connector for the tacho near the top of the guard from
>> memory passenger side of the car. It's a single terminal connector
>> that you can connect to a tacho.
>> You need to short two terminals on the DLC connector to put the ECU
>> into service mode. I can look it up if you need to know which two
>> terminals they are.
>>
>>
>>
>>
>
> If you can let me know the two terminals that would be great, I only
> have info regarding diagnostic mode. Also I have just cleaned the IAC
> and some how, it seems to be too long to go back in, measured about
> 37mm??? I gently pushed it back in, in a side to side motion until it
> fitted. Is there any problems in doing that or have I just damaged it?
>

You're not supposed to, but I've done it in the past and it hasn't caused
any problems. Don't lubricate it or spray solvents on it thoug and you must
clean the throttle body properly where the IAC pintle sits in situ.

The two terminals are A and B and a 10K resistor should be placed between
them to put the ECU into service mode. If you don't have a resistor, a bulb
type testlight (or just a bulb) between terminal B and earth will simulate
the resistance required to put the ECU into service mode.

You will know when you get it right because the idle will drop or the
vehicle may well stall.
Restart and adjust the base idle until a steady 400-500rpm is obtained. Then
you disconnect terminal B pull the fuse and go through the relearn
procedure.

Note that *shorting* terminals A and B is not the service mode but will
flash any trouble codes using the check engine lamp but is not the service
mode required to adjust base idle.

[Ext User(Klompmeester)]

<mmal380vrx@hotmail.com> wrote in message
news:081db72e-b598-4ac3-a1ce-0e6ce1016f35@s12g2000prg.googlegroups.com...
> On Dec 21, 8:52 pm, TJB <2lazyToGet@one> wrote:
>> The old VN has been running very well but lately has trouble with the
>> idle.
>> When you come to a stop, auto still in drive, i.e. at traffic lights, the
>> idle drops to about the normal level, just over half way on the dash
>> tacho
>> between 0 and 1000 rpm. (Unfortunately I only have an old rpm meter and I
>> am not sure how I would connect it to the VN for a more accurate
>> reading).
>> However after a short while the idle speed starts to slowly decrease to
>> just above the 0 on the tacho, where its start to vibrate more than
>> usual.
>> So far it has not actually konked out, just idles very low.
>>
>> The engine light flashes the usual 12. I have only checked then IAC by
>> simply unpluging it and seeing the rpm go very high at start and back to
>> normal when plugged back it. I have also disconnected the battery and run
>> the engne at >3000 rpm for 10 seconds. Unfortunately with lpg it's a pain
>> to remove the throttle body to measure IAC resistance. Leads are new (and
>> okay), as are the spark plugs.
>>
>> Anything else I should try or do? If I do remove the throttle anything
>> to
>> watch out for in cleaning/checking it??
>>
>> Thanks
>> TJB
>
> hahahaha its a holden you can expect more problems than just the idle
> trade it up for a magna instead because they are trouble free cars

True, 1989 vintage Magnas offer little resistance to the crushers.

[Ext User(Paul Saccani)]

On Sat, 22 Dec 2007 15:59:07 +0900, "Klompmeester"
<whowhere@andwhy.com> wrote:

>The two terminals are A and B and a 10K resistor should be placed between
>them to put the ECU into service mode. If you don't have a resistor, a bulb
>type testlight (or just a bulb) between terminal B and earth will simulate
>the resistance required to put the ECU into service mode.

ISTR 10 k resistor is for entering "high speed" data mode, rather than
field service mode, which is a simple short.
--
Cheers
Paul Saccani
Perth, Western Australia.

[Ext User(Klompmeester)]

"Paul Saccani" <saccani@omen.net.au> wrote in message
news:4s8qm3tc4fpq9ek5n661p1dr5k8o9ocfev@4ax.com...
> On Sat, 22 Dec 2007 15:59:07 +0900, "Klompmeester"
> <whowhere@andwhy.com> wrote:
>
>>The two terminals are A and B and a 10K resistor should be placed between
>>them to put the ECU into service mode. If you don't have a resistor, a
>>bulb
>>type testlight (or just a bulb) between terminal B and earth will simulate
>>the resistance required to put the ECU into service mode.
>
> ISTR 10 k resistor is for entering "high speed" data mode, rather than
> field service mode, which is a simple short.

According to my memory and this site, you got that wrong...

http://www.techedge.com.au/vehicle/aldl160/vn_aldl.htm

I've had to put hundreds of VN's into service mode to adjust the base idle
using a testlight and terminal B when Tech 1 wasn't available.

[Ext User(LSx-Australia)]

On Sat, 22 Dec 2007 16:14:47 +0900, Klompmeester PCM code reading says:


>>
>> hahahaha its a holden you can expect more problems than just the idle
>> trade it up for a magna instead because they are trouble free cars
>
> True, 1989 vintage Magnas offer little resistance to the crushers.

LOL
Yup trouble free in that area. :-)

--
Regards
Dan

[Ext User(TJB)]

"Klompmeester" <whowhere@andwhy.com> wrote in
news:13mpde74f0r5615@corp.supernews.com:

>
>
> You're not supposed to, but I've done it in the past and it hasn't
> caused any problems. Don't lubricate it or spray solvents on it thoug
> and you must clean the throttle body properly where the IAC pintle
> sits in situ.
>
> The two terminals are A and B and a 10K resistor should be placed
> between them to put the ECU into service mode. If you don't have a
> resistor, a bulb type testlight (or just a bulb) between terminal B
> and earth will simulate the resistance required to put the ECU into
> service mode.
>
> You will know when you get it right because the idle will drop or the
> vehicle may well stall.
> Restart and adjust the base idle until a steady 400-500rpm is
> obtained. Then you disconnect terminal B pull the fuse and go through
> the relearn procedure.
>
> Note that *shorting* terminals A and B is not the service mode but
> will flash any trouble codes using the check engine lamp but is not
> the service mode required to adjust base idle.
>
>
>
>
>
>
>

Thanks for your help. I have not lubricated the end or the stem but I
did cleaned the end with a toothbrush soaked in carby cleaner, also
cleaned the spring as a result of brushing the end clean. Then I put a
thin oil film around a new o-ring. I got the throttle body quite clean
including the well the IAC sits in. That was quite easy using a rag
dipped in carby cleaner and using one of those really big sponge
"cotten" buds for the passageway.

I can't seem to find the tacho lead you mentioned. I remember looking
for it a number of years ago and not finding it then either. I have not
touched or adjusted any screws so hopefully the car will just return to
its preset idle after I go through the learning process.


Thanks again for your help
TJB

[Ext User(Klompmeester)]

"TJB" <2lazyToGet@one> wrote in message
news:Xns9A0F7A8B0CCC4IDWhatID@216.168.3.72...
> "Klompmeester" <whowhere@andwhy.com> wrote in
> news:13mpde74f0r5615@corp.supernews.com:
>
>>
>>
>> You're not supposed to, but I've done it in the past and it hasn't
>> caused any problems. Don't lubricate it or spray solvents on it thoug
>> and you must clean the throttle body properly where the IAC pintle
>> sits in situ.
>>
>> The two terminals are A and B and a 10K resistor should be placed
>> between them to put the ECU into service mode. If you don't have a
>> resistor, a bulb type testlight (or just a bulb) between terminal B
>> and earth will simulate the resistance required to put the ECU into
>> service mode.
>>
>> You will know when you get it right because the idle will drop or the
>> vehicle may well stall.
>> Restart and adjust the base idle until a steady 400-500rpm is
>> obtained. Then you disconnect terminal B pull the fuse and go through
>> the relearn procedure.
>>
>> Note that *shorting* terminals A and B is not the service mode but
>> will flash any trouble codes using the check engine lamp but is not
>> the service mode required to adjust base idle.
>>
>>
>>
>>
>>
>>
>>
>
> Thanks for your help. I have not lubricated the end or the stem but I
> did cleaned the end with a toothbrush soaked in carby cleaner, also
> cleaned the spring as a result of brushing the end clean. Then I put a
> thin oil film around a new o-ring. I got the throttle body quite clean
> including the well the IAC sits in. That was quite easy using a rag
> dipped in carby cleaner and using one of those really big sponge
> "cotten" buds for the passageway.
>
> I can't seem to find the tacho lead you mentioned. I remember looking
> for it a number of years ago and not finding it then either. I have not
> touched or adjusted any screws so hopefully the car will just return to
> its preset idle after I go through the learning process.
>
>
> Thanks again for your help
> TJB

No probs. Gernerally the base idle doesn't need to be adjusted unless
someone has tampered with it so good luck.

[Ext User(Paul Saccani)]

On Sun, 23 Dec 2007 06:11:17 +0900, "Klompmeester"
<whowhere@andwhy.com> wrote:

>
>"Paul Saccani" <saccani@omen.net.au> wrote in message
>news:4s8qm3tc4fpq9ek5n661p1dr5k8o9ocfev@4ax.com...
>> On Sat, 22 Dec 2007 15:59:07 +0900, "Klompmeester"
>> <whowhere@andwhy.com> wrote:
>>
>>>The two terminals are A and B and a 10K resistor should be placed between
>>>them to put the ECU into service mode. If you don't have a resistor, a
>>>bulb
>>>type testlight (or just a bulb) between terminal B and earth will simulate
>>>the resistance required to put the ECU into service mode.
>>
>> ISTR 10 k resistor is for entering "high speed" data mode, rather than
>> field service mode, which is a simple short.
>
>According to my memory and this site, you got that wrong...
>
>http://www.techedge.com.au/vehicle/aldl160/vn_aldl.htm
>
>I've had to put hundreds of VN's into service mode to adjust the base idle
>using a testlight and terminal B when Tech 1 wasn't available.

With the greatest of respect, and not rubbishing anyone -

Evidently the knowledge of both yourself and the guy who wrote that
website is not entirely accurate, and is certainly less than full.

I say this on the basis of my memory of AC-Delco P4 units, and model
specific VN training by GMH, and by reference to my course notes on
that model, which I have dug up to check my facts. Not just on
muddling my way through without full understanding for hundreds of
times, but on doing it correctly and understanding what I was doing
hundreds of times.

The 160 baud mode which the site refers to as "vehicle service" or
tech-1 mode is the "high speed" (in quotes, 'cause 160 baud isn't
really fast) data mode to which I referred. I don't have any issue
with calling it vehicle service mode, but it is *not* what GMH call
"field service mode". The tool that GMH want you to use to enter
diagnostic/field service mode is a modified SD28079, which simply
makes a short.

What the site refers to as CEL mode is more or less correct (GMH call
it diagnostic mode), but, and the difference is crucial, with the
engine running it enters Field Service Mode.

Now, there is absolutely no point in entering the high speed data mode
if you don't have a means of reading the "high speed" signal, whilst
if you enter the correct Field Service Mode, you can do everything
that you did by using a 10 k resistor, specifically -

EST ignition timing fixed to 10° BTDC below 2000 RPM.

As to base idle - the IAC should be disconnected after 30 seconds of
key on, engine off in diagnostic mode, before commencing this.

*and*

In Field Service Mode, the CEL flashes to indicate closed or open loop
operation from the EGO, and whether you are running rich or lean, like
this -

Flashing 2.5 Hz - Open Loop.
Flashing 1 Hz - Closed Loop, correct mixture
Off most of the time - Closed Loop - Lean.
On most of the time - Closed Loop - Rich.

So basically, you've spent years using a 10 k resistor when you not
only didn't need to, but could also have gained some useful
information by using a simple short.

BTW, if anyone browses the site and comes to

http://www.techedge.com.au/vehicle/aldl160/aldl_hw.htm

and wants to make a VN/VP interface, and needs the connector, the tail
lamp wiring harness of the Hyundia Excel has got the correct
connector. I can't recall which year, sadly.


--
Cheers
Paul Saccani
Perth, Western Australia.

[Ext User(Paul Saccani)]

On Sun, 23 Dec 2007 01:30:16 -0000, TJB <2lazyToGet@one> wrote:

>"Klompmeester" <whowhere@andwhy.com> wrote in
>news:13mpde74f0r5615@corp.supernews.com:
>
>>
>>
>> You're not supposed to, but I've done it in the past and it hasn't
>> caused any problems. Don't lubricate it or spray solvents on it thoug
>> and you must clean the throttle body properly where the IAC pintle
>> sits in situ.
>>
>> The two terminals are A and B and a 10K resistor should be placed
>> between them to put the ECU into service mode. If you don't have a
>> resistor, a bulb type testlight (or just a bulb) between terminal B
>> and earth will simulate the resistance required to put the ECU into
>> service mode.
>>
>> You will know when you get it right because the idle will drop or the
>> vehicle may well stall.
>> Restart and adjust the base idle until a steady 400-500rpm is
>> obtained. Then you disconnect terminal B pull the fuse and go through
>> the relearn procedure.
>>
>> Note that *shorting* terminals A and B is not the service mode but
>> will flash any trouble codes using the check engine lamp but is not
>> the service mode required to adjust base idle.
>
>Thanks for your help. I have not lubricated the end or the stem but I
>did cleaned the end with a toothbrush soaked in carby cleaner, also
>cleaned the spring as a result of brushing the end clean. Then I put a
>thin oil film around a new o-ring. I got the throttle body quite clean
>including the well the IAC sits in. That was quite easy using a rag
>dipped in carby cleaner and using one of those really big sponge
>"cotten" buds for the passageway.
>
>I can't seem to find the tacho lead you mentioned. I remember looking
>for it a number of years ago and not finding it then either. I have not
>touched or adjusted any screws so hopefully the car will just return to
>its preset idle after I go through the learning process.

I forgot to mention, don't waste your time with the elaborate learning
process. You do need to pull the Eng. Comp. link to reset the
computer, but you don't need to fiddle around with A/C on off etc....,
and 1500 RPM is too low. Instead, you need to go to 3,000 RPM for 10
to 15 seconds, and that's it.
--
Cheers
Paul Saccani
Perth, Western Australia.

[Ext User(Klompmeester)]

"Paul Saccani" <saccani@omen.net.au> wrote in message
news:ct4sm396nge1ohh6ckahl4m4pnh0hajefr@4ax.com...
> On Sun, 23 Dec 2007 01:30:16 -0000, TJB <2lazyToGet@one> wrote:
>
>>"Klompmeester" <whowhere@andwhy.com> wrote in
>>news:13mpde74f0r5615@corp.supernews.com:
>>
>>>
>>>
>>> You're not supposed to, but I've done it in the past and it hasn't
>>> caused any problems. Don't lubricate it or spray solvents on it thoug
>>> and you must clean the throttle body properly where the IAC pintle
>>> sits in situ.
>>>
>>> The two terminals are A and B and a 10K resistor should be placed
>>> between them to put the ECU into service mode. If you don't have a
>>> resistor, a bulb type testlight (or just a bulb) between terminal B
>>> and earth will simulate the resistance required to put the ECU into
>>> service mode.
>>>
>>> You will know when you get it right because the idle will drop or the
>>> vehicle may well stall.
>>> Restart and adjust the base idle until a steady 400-500rpm is
>>> obtained. Then you disconnect terminal B pull the fuse and go through
>>> the relearn procedure.
>>>
>>> Note that *shorting* terminals A and B is not the service mode but
>>> will flash any trouble codes using the check engine lamp but is not
>>> the service mode required to adjust base idle.
>>
>>Thanks for your help. I have not lubricated the end or the stem but I
>>did cleaned the end with a toothbrush soaked in carby cleaner, also
>>cleaned the spring as a result of brushing the end clean. Then I put a
>>thin oil film around a new o-ring. I got the throttle body quite clean
>>including the well the IAC sits in. That was quite easy using a rag
>>dipped in carby cleaner and using one of those really big sponge
>>"cotten" buds for the passageway.
>>
>>I can't seem to find the tacho lead you mentioned. I remember looking
>>for it a number of years ago and not finding it then either. I have not
>>touched or adjusted any screws so hopefully the car will just return to
>>its preset idle after I go through the learning process.
>
> I forgot to mention, don't waste your time with the elaborate learning
> process. You do need to pull the Eng. Comp. link to reset the
> computer, but you don't need to fiddle around with A/C on off etc....,
> and 1500 RPM is too low. Instead, you need to go to 3,000 RPM for 10
> to 15 seconds, and that's it.

I'll grant you the latter 3000rpm instead of 1500rpm although it makes no
difference as all it's doing is stopping the engine from stalling as the ECU
winds the pintle all the way in to get it's position. The relearn is a good
idea, and following the correct procedure for doing a TB service. For one
you can hear the IAC reducing the idle speed so you know it's working.