closed loop mode

[Andre]

Hi Guys,

I have a question regarding my 1989 VN commodore which is having rough
idling problems. Should it go into closed loop o2 sensor mode at idle
as it does not appear to be doing so. Closed loop mode appears to
working fine at anything above idle. Is this normal behaviour?

Andre

[John_H]

Andre wrote:

>
>I have a question regarding my 1989 VN commodore which is having rough
>idling problems. Should it go into closed loop o2 sensor mode at idle
>as it does not appear to be doing so. Closed loop mode appears to
>working fine at anything above idle. Is this normal behaviour?

Idle mode is open loop -- ie engine should always run slightly richer
than stoichiometric at idle.

--
John H

[Julian Edgar]

"John_H" <john4271@hotmail.com> wrote in message
news:lgni11dei3n8rfr91hogcsdgc1naev2rg4@4ax.com...
> Andre wrote:
>
>>
>>I have a question regarding my 1989 VN commodore which is having rough
>>idling problems. Should it go into closed loop o2 sensor mode at idle
>>as it does not appear to be doing so. Closed loop mode appears to
>>working fine at anything above idle. Is this normal behaviour?
>
> Idle mode is open loop -- ie engine should always run slightly richer
> than stoichiometric at idle.
>
> --
> John H

Not so - idle is always in closed loop when engine has warmed up.

Julian Edgar

[John_H]

Julian Edgar wrote:

>
>"John_H" <john4271@hotmail.com> wrote in message
>news:lgni11dei3n8rfr91hogcsdgc1naev2rg4@4ax.com...
>>
>> Idle mode is open loop -- ie engine should always run slightly richer
>> than stoichiometric at idle.

>
>Not so - idle is always in closed loop when engine has warmed up.

From the VN service manual....

"The reason for the Idle Mode is to allow a slightly richer
mixture for better idle quality. Idle Mode air/fuel ratio is about
14.0 to 1. This is open loop mode, meaning the O2 sensor signal is
ignored
The idle mode is in effect when the throttle is closed (TPS), and
vehicle speed is below 5 km/h (VSS)."

--
John H

[Julian Edgar]

"John_H" <john4271@hotmail.com> wrote in message
news:55si11dvuu85ngk9r671s6inosk45c29td@4ax.com...
> Julian Edgar wrote:
>
>>
>>"John_H" <john4271@hotmail.com> wrote in message
>>news:lgni11dei3n8rfr91hogcsdgc1naev2rg4@4ax.com...
>>>
>>> Idle mode is open loop -- ie engine should always run slightly richer
>>> than stoichiometric at idle.
>
>>
>>Not so - idle is always in closed loop when engine has warmed up.
>
> From the VN service manual....
>
> "The reason for the Idle Mode is to allow a slightly richer
> mixture for better idle quality. Idle Mode air/fuel ratio is about
> 14.0 to 1. This is open loop mode, meaning the O2 sensor signal is
> ignored
> The idle mode is in effect when the throttle is closed (TPS), and
> vehicle speed is below 5 km/h (VSS)."
>
> --
> John H

Thanks - I stand corrected!

Julian Edgar

[sheik yerbouti]

On 20 Feb 2005 18:49:19 -0800, schmickla@hotmail.com (Andre) wrote:

>Hi Guys,
>
>I have a question regarding my 1989 VN commodore which is having rough
>idling problems. Should it go into closed loop o2 sensor mode at idle
>as it does not appear to be doing so. Closed loop mode appears to
>working fine at anything above idle. Is this normal behaviour?

try removing the throttle body, cleaning out the butterfly and the
IACV.

or bring it down to my garage and i can take a look.

---
sheik's auto service centre
88 Wilsons Rd Doncaster 3108
(03) 9855 8777, http://www.freewebs.com/sheik_yerbouti
specialising in transmission service

[Toby Ponsenby]

On Mon, 21 Feb 2005 16:05:38 +1000, Julian Edgar wrote:

> "John_H" <john4271@hotmail.com> wrote in message
> news:55si11dvuu85ngk9r671s6inosk45c29td@4ax.com...
>> Julian Edgar wrote:
>>
>>>
>>>"John_H" <john4271@hotmail.com> wrote in message
>>>news:lgni11dei3n8rfr91hogcsdgc1naev2rg4@4ax.com...
>>>>
>>>> Idle mode is open loop -- ie engine should always run slightly richer
>>>> than stoichiometric at idle.
>>
>>>
>>>Not so - idle is always in closed loop when engine has warmed up.
>>
>> From the VN service manual....
>>
>> "The reason for the Idle Mode is to allow a slightly richer
>> mixture for better idle quality. Idle Mode air/fuel ratio is about
>> 14.0 to 1. This is open loop mode, meaning the O2 sensor signal is
>> ignored
>> The idle mode is in effect when the throttle is closed (TPS), and
>> vehicle speed is below 5 km/h (VSS)."
>>
>> --
>> John H
>
> Thanks - I stand corrected!
>
> Julian Edgar

Sometimes he's a bad man... :-)

--
Toby
quidquid latine dictum
sit, altum viditur

[Toby Ponsenby]

On Mon, 21 Feb 2005 17:28:27 +1100, sheik yerbouti wrote:

> On 20 Feb 2005 18:49:19 -0800, schmickla@hotmail.com (Andre) wrote:
>
>>Hi Guys,
>>
>>I have a question regarding my 1989 VN commodore which is having rough
>>idling problems. Should it go into closed loop o2 sensor mode at idle
>>as it does not appear to be doing so. Closed loop mode appears to
>>working fine at anything above idle. Is this normal behaviour?
>
> try removing the throttle body, cleaning out the butterfly and the
> IACV.
>
> or bring it down to my garage and i can take a look.
>
> ---
> sheik's auto service centre
> 88 Wilsons Rd Doncaster 3108
> (03) 9855 8777, http://www.freewebs.com/sheik_yerbouti
> specialising in transmission service

Ripper, Boris!!

--
Toby
quidquid latine dictum
sit, altum viditur

[Serialpest]

On 21/2/05 4:28 PM, in article sqvi11hp3jv16156cac4kn4iarmshbe000@4ax.com,
"sheik yerbouti" <delbo21@yahoo.com> wrote:

> On 20 Feb 2005 18:49:19 -0800, schmickla@hotmail.com (Andre) wrote:
>
>> Hi Guys,
>>
>> I have a question regarding my 1989 VN commodore which is having rough
>> idling problems. Should it go into closed loop o2 sensor mode at idle
>> as it does not appear to be doing so. Closed loop mode appears to
>> working fine at anything above idle. Is this normal behaviour?
>
> try removing the throttle body, cleaning out the butterfly and the
> IACV.
>
> or bring it down to my garage and i can take a look.
>
> ---
> sheik's auto service centre
> 88 Wilsons Rd Doncaster 3108
> (03) 9855 8777, http://www.freewebs.com/sheik_yerbouti
> specialising in transmission service

Oh shit he's gonna put it up on those stands.

[Clockmeister]

"Andre" <schmickla@hotmail.com> wrote in message
news:882003e8.0502201849.4b93b3dd@posting.google.c om...
> Hi Guys,
>
> I have a question regarding my 1989 VN commodore which is having rough
> idling problems. Should it go into closed loop o2 sensor mode at idle
> as it does not appear to be doing so. Closed loop mode appears to
> working fine at anything above idle. Is this normal behaviour?
>

Yep.

The rough idle is caused by a clogged throttle body and caked IAC pintle and
possibly a need for base idle adjustment and relearn.

Do a search in google groups for my detailed instructions on how to do a
throttle body service on the Holden V6 as I've posted the procedure a couple
of times already in this group.

and check this thread and similar ones...

http://groups.google.com.au/groups?hl=en&lr=&safe=off&threadm=417d9cc4%40duster.adelaide.on.net&rnum=1&prev=/groups%3Fq%3Diac%2Bprocedure%2Bclockmeister%26hl%3 Den%26lr%3D%26safe%3Doff%26selm%3D417d9cc4%2540dus ter.adelaide.on.net%26rnum%3D1

Regards,

Clockmeister.

[Andre]

schmickla@hotmail.com (Andre) wrote in message news:<882003e8.0502201849.4b93b3dd@posting.google.com>...
> Hi Guys,
>
> I have a question regarding my 1989 VN commodore which is having rough
> idling problems. Should it go into closed loop o2 sensor mode at idle
> as it does not appear to be doing so. Closed loop mode appears to
> working fine at anything above idle. Is this normal behaviour?
>
> Andre

>>Yep.

>>The rough idle is caused by a clogged throttle body and caked IAC
pintle and
>>possibly a need for base idle adjustment and relearn.

>>Do a search in google groups for my detailed instructions on how to
do a
>>throttle body service on the Holden V6 as I've posted the procedure
a couple
>>of times already in this group.

>>and check this thread and similar ones...

>>http://groups.google.com.au/groups?hl=en&lr=&safe=off&threadm=417d9cc4%>>40duster.adelaide.on.net&rnum=1&prev=/groups%3Fq%3Diac%2Bprocedure%>>2Bclockmeister%26hl%3Den%26lr%3D%26safe%3Doff%26se lm%3D417d9cc4%>>2540duster.adelaide.on.net%26rnum%3D1

>>Regards,

>>Clockmeister.

Thanx Clockmeister, although I have tried cleaning the throttle body I
may not have done a thorough job so I will try again. I don't think
there is a problem with the IAC as it appears to be reacting fine to
changes in idle load. The base idle may need adjusting as you said. I
will let you know how I go.

Andre

[Clockmeister]

"Andre" <schmickla@hotmail.com> wrote in message
news:882003e8.0502211902.6dd4db0f@posting.google.c om...
> schmickla@hotmail.com (Andre) wrote in message
news:<882003e8.0502201849.4b93b3dd@posting.google.com>...
> > Hi Guys,
> >
> > I have a question regarding my 1989 VN commodore which is having rough
> > idling problems. Should it go into closed loop o2 sensor mode at idle
> > as it does not appear to be doing so. Closed loop mode appears to
> > working fine at anything above idle. Is this normal behaviour?
> >
> > Andre
>
> >>Yep.
>
> >>The rough idle is caused by a clogged throttle body and caked IAC
> pintle and
> >>possibly a need for base idle adjustment and relearn.
>
> >>Do a search in google groups for my detailed instructions on how to
> do a
> >>throttle body service on the Holden V6 as I've posted the procedure
> a couple
> >>of times already in this group.
>
> >>and check this thread and similar ones...
>
>
>>http://groups.google.com.au/groups?hl=en&lr=&safe=off&threadm=417d9cc4%>>4
0duster.adelaide.on.net&rnum=1&prev=/groups%3Fq%3Diac%2Bprocedure%>>2Bclockm
eister%26hl%3Den%26lr%3D%26safe%3Doff%26selm%3D417 d9cc4%>>2540duster.adelaid
e.on.net%26rnum%3D1
>
> >>Regards,
>
> >>Clockmeister.
>
> Thanx Clockmeister, although I have tried cleaning the throttle body I
> may not have done a thorough job so I will try again. I don't think
> there is a problem with the IAC as it appears to be reacting fine to
> changes in idle load. The base idle may need adjusting as you said. I
> will let you know how I go.
>

If you don't remove and clean the IAC properly you are wasting your time. It
is the #1 reason for poor idle quality on VN/VP.

Do it properly, it's not hard.

[Toby Ponsenby]

On Tue, 22 Feb 2005 15:45:45 +0800, Clockmeister wrote:

> "Andre" <schmickla@hotmail.com> wrote in message
> news:882003e8.0502211902.6dd4db0f@posting.google.c om...
>> schmickla@hotmail.com (Andre) wrote in message
> news:<882003e8.0502201849.4b93b3dd@posting.google.com>...
>>> Hi Guys,
>>>
>>> I have a question regarding my 1989 VN commodore which is having rough
>>> idling problems. Should it go into closed loop o2 sensor mode at idle
>>> as it does not appear to be doing so. Closed loop mode appears to
>>> working fine at anything above idle. Is this normal behaviour?
>>>
>>> Andre
>>
>>>>Yep.
>>
>>>>The rough idle is caused by a clogged throttle body and caked IAC
>> pintle and
>>>>possibly a need for base idle adjustment and relearn.
>>
>>>>Do a search in google groups for my detailed instructions on how to
>> do a
>>>>throttle body service on the Holden V6 as I've posted the procedure
>> a couple
>>>>of times already in this group.
>>
>>>>and check this thread and similar ones...
>>
>>
>>>http://groups.google.com.au/groups?hl=en&lr=&safe=off&threadm=417d9cc4%>>4
> 0duster.adelaide.on.net&rnum=1&prev=/groups%3Fq%3Diac%2Bprocedure%>>2Bclockm
> eister%26hl%3Den%26lr%3D%26safe%3Doff%26selm%3D417 d9cc4%>>2540duster.adelaid
> e.on.net%26rnum%3D1
>>
>>>>Regards,
>>
>>>>Clockmeister.
>>
>> Thanx Clockmeister, although I have tried cleaning the throttle body I
>> may not have done a thorough job so I will try again. I don't think
>> there is a problem with the IAC as it appears to be reacting fine to
>> changes in idle load. The base idle may need adjusting as you said. I
>> will let you know how I go.
>>
>
> If you don't remove and clean the IAC properly you are wasting your time. It
> is the #1 reason for poor idle quality on VN/VP.
>
> Do it properly, it's not hard.

Do the V6 Commodores attempt to maintain negative crankcase pressure?
--
Toby
quidquid latine dictum
sit, altum viditur

[Clockmeister]

"Toby Ponsenby" <toby@privacy.net> wrote in message
news:v65b2azmw4i9$.waf66kptln93.dlg@40tude.net...
> On Tue, 22 Feb 2005 15:45:45 +0800, Clockmeister wrote:
>
> > "Andre" <schmickla@hotmail.com> wrote in message
> > news:882003e8.0502211902.6dd4db0f@posting.google.c om...
> >> schmickla@hotmail.com (Andre) wrote in message
> > news:<882003e8.0502201849.4b93b3dd@posting.google.com>...
> >>> Hi Guys,
> >>>
> >>> I have a question regarding my 1989 VN commodore which is having rough
> >>> idling problems. Should it go into closed loop o2 sensor mode at idle
> >>> as it does not appear to be doing so. Closed loop mode appears to
> >>> working fine at anything above idle. Is this normal behaviour?
> >>>
> >>> Andre
> >>
> >>>>Yep.
> >>
> >>>>The rough idle is caused by a clogged throttle body and caked IAC
> >> pintle and
> >>>>possibly a need for base idle adjustment and relearn.
> >>
> >>>>Do a search in google groups for my detailed instructions on how to
> >> do a
> >>>>throttle body service on the Holden V6 as I've posted the procedure
> >> a couple
> >>>>of times already in this group.
> >>
> >>>>and check this thread and similar ones...
> >>
> >>
>
>>>http://groups.google.com.au/groups?hl=en&lr=&safe=off&threadm=417d9cc4%>>
4
> >
0duster.adelaide.on.net&rnum=1&prev=/groups%3Fq%3Diac%2Bprocedure%>>2Bclockm
> >
eister%26hl%3Den%26lr%3D%26safe%3Doff%26selm%3D417 d9cc4%>>2540duster.adelaid
> > e.on.net%26rnum%3D1
> >>
> >>>>Regards,
> >>
> >>>>Clockmeister.
> >>
> >> Thanx Clockmeister, although I have tried cleaning the throttle body I
> >> may not have done a thorough job so I will try again. I don't think
> >> there is a problem with the IAC as it appears to be reacting fine to
> >> changes in idle load. The base idle may need adjusting as you said. I
> >> will let you know how I go.
> >>
> >
> > If you don't remove and clean the IAC properly you are wasting your
time. It
> > is the #1 reason for poor idle quality on VN/VP.
> >
> > Do it properly, it's not hard.
>
> Do the V6 Commodores attempt to maintain negative crankcase pressure?

No, not like the early EFI Fords where a weepy seal can cause poor idle, if
that is what you mean.

[Toby Ponsenby]

On Tue, 22 Feb 2005 16:05:09 +0800, Clockmeister wrote:

>>> If you don't remove and clean the IAC properly you are wasting your
> time. It
>>> is the #1 reason for poor idle quality on VN/VP.
>>>
>>> Do it properly, it's not hard.
>>
>> Do the V6 Commodores attempt to maintain negative crankcase pressure?
>
> No, not like the early EFI Fords where a weepy seal can cause poor idle, if
> that is what you mean.

Almost..
I recall much to do about Toyotas and their neg crankcase pressure
character. The symptom is blow-by evident - where the cars behave like
they used-ta.
In that application, the whole engine turns to shite if the wee
passages in the throttle body and elsewhere (yes, IAC valve is in
there in spades) clog up. And they do.
In fact there's a Guru on the Cressida yahoo group that posted a
monster 'how-to' on maintaining that system to within an inch of its
life. (Guru = real live vastly experienced but retired unhurt tech
trainer for Canada)
His view on the matter is that if that neg pressure going bad is the
real cause of HG failures and myriad other misbehaviours of what he
sees as a good piece of autobuilding.

I was thinking if the problem set was even remotely similar GM to
Toyota, I'd post his piece here. Good read. He's unashamedly
pro-Toyota though, so I'd have to add a disclaimer that I own all
sorts of other stuff. Else I'd be branded a Toyotaphile rather than a
common or garden variety nut-case.


--
Toby
quidquid latine dictum
sit, altum viditur

[sheik yerbouti]

On Mon, 21 Feb 2005 17:56:35 +1000, Serialpest
<V8beater@mitsubishi.com> wrote:

>> try removing the throttle body, cleaning out the butterfly and the
>> IACV.
>>
>> or bring it down to my garage and i can take a look.

>Oh shit he's gonna put it up on those stands.

FYI my commodore is still up on those stands and doing fine

---
sheik's auto service centre
88 Wilsons Rd Doncaster 3108
(03) 9855 8777, http://www.freewebs.com/sheik_yerbouti
specialising in transmission service

[sheik yerbouti]

On 21 Feb 2005 19:02:03 -0800, schmickla@hotmail.com (Andre) wrote:


>
>Thanx Clockmeister, although I have tried cleaning the throttle body I
>may not have done a thorough job so I will try again. I don't think
>there is a problem with the IAC as it appears to be reacting fine to
>changes in idle load. The base idle may need adjusting as you said. I
>will let you know how I go.

you aren't supposed (or able) to set the base idle on a VN. that is
the job of the IACV.

you only touch the stop-screw if it's "getting in the way", which it
really shouldn't unless you've fucked it up yourself.

---
sheik's auto service centre
88 Wilsons Rd Doncaster 3108
(03) 9855 8777, http://www.freewebs.com/sheik_yerbouti
specialising in transmission service

[sheik yerbouti]

On Tue, 22 Feb 2005 18:49:02 +1000, Toby Ponsenby <toby@privacy.net>
wrote:

>>
>> No, not like the early EFI Fords where a weepy seal can cause poor idle, if
>> that is what you mean.
>
>Almost..
>I recall much to do about Toyotas and their neg crankcase pressure
>character. The symptom is blow-by evident - where the cars behave like
>they used-ta.

why do toyota go for a neg c/case pressure?

---
sheik's auto service centre
88 Wilsons Rd Doncaster 3108
(03) 9855 8777, http://www.freewebs.com/sheik_yerbouti
specialising in transmission service

[atec]

Toby Ponsenby wrote:
> On Tue, 22 Feb 2005 16:05:09 +0800, Clockmeister wrote:
>
>
>
>
> I was thinking if the problem set was even remotely similar GM to
> Toyota, I'd post his piece here. Good read. He's unashamedly
> pro-Toyota though, so I'd have to add a disclaimer that I own all
> sorts of other stuff. Else I'd be branded a Toyotaphile rather than a
> common or garden variety nut-case.
>
>
can you post a link to a host with disclaimer ?

[Clockmeister]

"sheik yerbouti" <delbo21@yahoo.com> wrote in message
news:13vl1153j969kqilrt7lm1dmd466kthjaa@4ax.com...
> On 21 Feb 2005 19:02:03 -0800, schmickla@hotmail.com (Andre) wrote:
>
>
> >
> >Thanx Clockmeister, although I have tried cleaning the throttle body I
> >may not have done a thorough job so I will try again. I don't think
> >there is a problem with the IAC as it appears to be reacting fine to
> >changes in idle load. The base idle may need adjusting as you said. I
> >will let you know how I go.
>
> you aren't supposed (or able) to set the base idle on a VN. that is
> the job of the IACV.

Rubbish. The base idle setting is completely seperate to the IACV.

> you only touch the stop-screw if it's "getting in the way", which it
> really shouldn't unless you've fucked it up yourself.
>

You don't touch it unless you follow the procedure that I have outlined
previously to the letter to set the base idle.

PS You shouldn't be touching cars at all, you have nfi.