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Rico_Avant
Joined: 05/04/2008 Posts: 36 Karma: +0 / -0
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10-08-2008, 20:43 Subject: Measurements |
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Hello everyone, yesterday I took a trip with my laptop and routinely checked the measurement data blocks, and I noticed the following. Everything was read in idle:
Block 1: Injected quantity should: 3.0-8.0, mine was 8.5
Block 3: Maf should: 180-270, with an average of around 800, +/-5
and why does Valve show 65% for cold start?
It was 35°C outside, and the engine had been running at its normal operating temperature for about half an hour.
Yes, these are the things that I noticed. Could you tell me what this means? A6 2.5 Tdi AFB with Tiptronic, Year of Manufacture: 98
Translated on 03-07-2026, 15:19.
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Jan6K

Joined: 04/12/2002 Posts: 4741 Karma: +107 / -0 Location: Hagen
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10-08-2008, 21:29 Subject: Measurements |
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Hi,
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Block 3: Maf should: 180-270, with an average of around 800, +/-5
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Is your AGR randomly malfunctioning? This would explain the high values, because in this case, significantly more air is being sucked in (instead of the exhaust gas, which should be sucked in).
Otherwise: Please give your thread a more impactful title via edit... "Measurements" says everything and nothing.
Best regards,
Jan 1Z5 CFHF  / AHB H4D 
Translated on 03-07-2026, 15:19.
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christians Profi-Schrauber

Joined: 09/05/2002 Posts: 2105 Karma: +17 / -0 Location: Sauerland
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10-08-2008, 22:23 Subject: Measurements |
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800 is not possible at idle; with a faulty AGR, it's around 400 mg/stroke. This could only be due to a faulty O2 sensor or the control unit. The name "Coldstartvalve" is misleading, it is the fuel injection adjustment valve; 65% is already okay. Gruß Christian
A6 BPP, Ex-A6 AKN (Gurke), Ex-Audi100 92 AAT (5Zyl.)
Translated on 03-07-2026, 15:19.
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Rico_Avant
Joined: 05/04/2008 Posts: 36 Karma: +0 / -0
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13-08-2008, 21:51 Subject: Measurements |
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So, there isn't really a traditional AGR (Exhaust Gas Recirculation) system on my engine anymore, because where there used to be a connection between the AGR valve and the intake manifold, there are now two metal plates instead of a pipe.
Could you please explain this value? Just wanted to have only fresh gases 
Translated on 03-07-2026, 15:19.
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guste100 Profi-Schrauber


Joined: 07/27/2004 Posts: 2399 Karma: +435 / -0 Location: Mitte Schleswig Holsteins 2007 Volkswagen Passat Premium Support
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14-08-2008, 8:59 Subject: Measurements |
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As Christians rightly points out, 800 is also unusually high even with a defective AGR.
This looks like unprofessional "chiptuning" where the soot limit has been disabled in this way. But this is just a pure assumption. Alternatively, a diode can also be used instead of the O2 sensor.
Greetings
Guste
Translated on 03-07-2026, 15:19.
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Rico_Avant
Joined: 05/04/2008 Posts: 36 Karma: +0 / -0
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14-08-2008, 16:06 Subject: Measurements |
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So, there is no chip tuning or diode installed on the car. I've already ordered a new O2 sensor and we'll see what happens then.
The previous owner had previously installed a Speedbuster powerbox from Speedbuster, which was rated for 180 hp, and it was even registered. If this has anything to do with the current issue, 
Translated on 03-07-2026, 15:19.
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