# CIS-E III dpr current fluctuation range



## vonniq (Nov 7, 2005)

Hi all,
What is the usual dpr current fluctuation range for CIS-E III system? Recently after replace a new water temp sensor (previously was on wrong sensor, causes no cold enrichment and frequent continuous knocking/pinging), now the ignition timing seems retarded (or misfire, but cold enrichment is ok and no more pinging), so I try to advance the ignition timing. 

I noticed as the ignition timing advance, the dpr current fluctuation range increase. Before it was somewhere between -1.5 to + 1.2 mA, but idle rpm will climb up very slowly and feels misfiring when doing hot starting. After ignition timing advance, the dpr current fluctuation "shift" towards to +ve range, I managed to adjust it till -2.5 to + 2.8mA range, is this normal? But now I can feel the idle fluctuate too as the dpr current fluctuate. Hot starting seems great as the idle rpm will raises to 1,000rpm immediately, still can hear knocking occasionally but it will goes away in a second. Is this the safe ignition timing point?

Car is Audi 100, AAR 2.3E engine, same as NF/NG engine. The problem arises after the engine overhauled and cylinder head skimming on last year. Until today only I found the culprit was the wrong water temp sensor.

Thank you.


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## vonniq (Nov 7, 2005)

Nobody can help? Should I retard the ignition timing?


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## offroader944s (Jul 3, 2008)

normal current on CIS E for VWs when at operating temp, is 4-16mA (8V) 1-10mA (16V). not sure if Audi is same.


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## vonniq (Nov 7, 2005)

offroader944s said:


> normal current on CIS E for VWs when at operating temp, is 4-16mA (8V) 1-10mA (16V). not sure if Audi is same.


I think for audi CIS-EIII, the central point is 0mA, so it should fluctuate around that value. Anyway, the car runs ok, so I guess the wide fluctuation range is still acceptable.


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## ziddey (Apr 16, 2006)

Have you been following this website: http://www.humanspeakers.com/audi/timing3.htm ?

Have you made sure you don't have any lingering vacuum leaks? How new is your oxygen sensor? Does your dpr current fluctuate evenly? Or does it seem to slowly drop, and then spike up and start slowing dropping again? I've had that problem with slow o2 sensors.


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## vonniq (Nov 7, 2005)

ziddey said:


> Have you been following this website: http://www.humanspeakers.com/audi/timing3.htm ?


Yes, I learned how to check the dpr current from there...



ziddey said:


> Have you made sure you don't have any lingering vacuum leaks?


Most vacuum hoses just replaced few months ago.



ziddey said:


> How new is your oxygen sensor?


18 years old, never replace yet.



ziddey said:


> Or does it seem to slowly drop, and then spike up and start slowing dropping again? I've had that problem with slow o2 sensors.


The engine idle always slowly drop, spice up, and slowly drop again everyday during engine warm-up, but is smoother after warm-up. So it's because of slow response from O2 sensor?


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