CIS tuning

Sat Jan 23 09:21:42 PST 2016

If you want to have this setup for monitoring, check your wideband
specs for a narrow band output (0-1v). I did exactly as you and put
the wideband O2 into the downpipe, for AFR readings, but wanted to
keep the narrowband readings going into the computer.

I'm using a zeitronix zt2 wideband, and it has a narrow band output
you can connect to the input for the computer (Mac11 on a 5k turbo)
for the narrowband O2 sensor.

I'll see if I have any old logging files from this setup, I would
normally just go for a drive and check, but the car is still in
pieces.

Jonathan

On Sat, Jan 23, 2016 at 12:03 PM, Nicholas Miller <chance9121 at gmail.com> wrote:
> I'm not 100% you are going to run correctly with the 02 sensor removed from
> the exhaust.  At WOT, you are on closed loop, not refering to the O2, but
> if you are part throttling it 'even at high rpms you will be referencing
> the O2 sensor, though I am not sure what percentage of throttle it would
> change over.
>
> I'm with DeWitt,  I would smoke test it first to find any air leaks.  If,
> at wot you are running lean, an unmetered air leak would be a very simple
> explanation.  As well, I had a really bad one a long time ago on my 5kqt at
> the igloo which was not easy to see visually until you removed it and
> checked on the bottom of it.
>
> Good luck,
>
> Nick
>
>
> On Fri, Jan 22, 2016 at 6:30 PM, DeWitt Harrison <dewitt635 at gmail.com>
> wrote:
>
>> On Thu, 21 Jan 2016 15:40:36 -0800 radek at uniserve.com wrote:
>> <radek at uniserve.com>
>>
>> > Hello all surviving CIS fans :)
>> >
>> > I decided to finally tackle the high idle problem in my winter ride,
>> > an 88 90Q.  I borrowed a wide-band O2 gauge, showing actual
>> > air-to-fuel ratio.  For now, I just removed the existing O2 sensor,
>> > replaced with the gauge's sensor and fired up the car.  First, it was
>> > running very rich, until it warmed up.  Once warm, the mix would be
>> > around 14:1 at idle, but would get very lean at higher rpms, up to 17:1.
>> >
>> > Are these results meaningful at all, without O2 sensor connected?
>> >
>> > The gauge has an output wire that can simulate O2 output to the ECU,
>> > which can be set (in low-voltage mode) to between 0 - 1 V.  According
>> > to Huw's page, this is the range a regular O2 sensor operates on?
>> > Just want to double check, wouldn't want to fry my ECU.
>> > Thanks for any input and guidance,
>> >
>> > Radek.
>>
>> Provided all the CIS sensors, such as the stock, narrow band O2 sensor,
>> temperature sensors, and the essential idle control items such as the idle
>> control air valve, air flow meter adjusting screw, etc., are working, just
>> follow the factory procedure (Bentley) to properly set the idle control air
>> valve duty cycle. To do this easily, you will need a couple of DVMs and a
>> made up test cable to put in series with the ICV. (Gross air leaks from
>> cracked hoses would have to be addressed beforehand as well.) Other than
>> that, there is not a whole lot to be done to adjust AFR at other operating
>> conditions although some CIS tuners have messed with trick control
>> pressures and other weird stuff (Hello Scott J.!) to get richer AFR at WOT.
>>
>> DeWitt Harrison
>> 1988 5ktq
>> _______________________________________________
>> quattro mailing list
>> http://www.audifans.com/mailman/listinfo/quattro
>> http://www.audifans.com/kb/List_information
> _______________________________________________
> quattro mailing list
> http://www.audifans.com/mailman/listinfo/quattro
> http://www.audifans.com/kb/List_information

On Sat, Jan 23, 2016 at 12:03 PM, Nicholas Miller <chance9121 at gmail.com> wrote:
> I'm not 100% you are going to run correctly with the 02 sensor removed from
> the exhaust.  At WOT, you are on closed loop, not refering to the O2, but
> if you are part throttling it 'even at high rpms you will be referencing
> the O2 sensor, though I am not sure what percentage of throttle it would
> change over.
>
> I'm with DeWitt,  I would smoke test it first to find any air leaks.  If,
> at wot you are running lean, an unmetered air leak would be a very simple
> explanation.  As well, I had a really bad one a long time ago on my 5kqt at
> the igloo which was not easy to see visually until you removed it and
> checked on the bottom of it.
>
> Good luck,
>
> Nick
>
>
> On Fri, Jan 22, 2016 at 6:30 PM, DeWitt Harrison <dewitt635 at gmail.com>
> wrote:
>
>> On Thu, 21 Jan 2016 15:40:36 -0800 radek at uniserve.com wrote:
>> <radek at uniserve.com>
>>
>> > Hello all surviving CIS fans :)
>> >
>> > I decided to finally tackle the high idle problem in my winter ride,
>> > an 88 90Q.  I borrowed a wide-band O2 gauge, showing actual
>> > air-to-fuel ratio.  For now, I just removed the existing O2 sensor,
>> > replaced with the gauge's sensor and fired up the car.  First, it was
>> > running very rich, until it warmed up.  Once warm, the mix would be
>> > around 14:1 at idle, but would get very lean at higher rpms, up to 17:1.
>> >
>> > Are these results meaningful at all, without O2 sensor connected?
>> >
>> > The gauge has an output wire that can simulate O2 output to the ECU,
>> > which can be set (in low-voltage mode) to between 0 - 1 V.  According
>> > to Huw's page, this is the range a regular O2 sensor operates on?
>> > Just want to double check, wouldn't want to fry my ECU.
>> > Thanks for any input and guidance,
>> >
>> > Radek.
>>
>> Provided all the CIS sensors, such as the stock, narrow band O2 sensor,
>> temperature sensors, and the essential idle control items such as the idle
>> control air valve, air flow meter adjusting screw, etc., are working, just
>> follow the factory procedure (Bentley) to properly set the idle control air
>> valve duty cycle. To do this easily, you will need a couple of DVMs and a
>> made up test cable to put in series with the ICV. (Gross air leaks from
>> cracked hoses would have to be addressed beforehand as well.) Other than
>> that, there is not a whole lot to be done to adjust AFR at other operating
>> conditions although some CIS tuners have messed with trick control
>> pressures and other weird stuff (Hello Scott J.!) to get richer AFR at WOT.
>>
>> DeWitt Harrison
>> 1988 5ktq
>> _______________________________________________
>> quattro mailing list
>> http://www.audifans.com/mailman/listinfo/quattro
>> http://www.audifans.com/kb/List_information
> _______________________________________________
> quattro mailing list
> http://www.audifans.com/mailman/listinfo/quattro
> http://www.audifans.com/kb/List_information