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MWB13: Performance Above Idle Speed

 
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donalexo
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Post10-01-2005, 20:45    Subject: MWB13: Performance Above Idle Speed Quote

Hello everyone!

Yesterday, I accidentally created a log file that included data related to the MWB13 (idle speed control).
I noticed that the values diverge quite a bit at higher speeds and loads, sometimes even approaching the 3mg/R limit icon_eek.gif.
At idle, the reading is a maximum of 0.6 mg/L.

However, I do wonder whether it's even worthwhile to evaluate these values. The fact is that the VP37 will not be able to adjust the quantity difference for each cylinder at significantly higher speeds.
But on the other hand, these values should still be an indicator of the differences in performance between the individual cylinders, right?
Interestingly, there's even a sign change between idle and higher load and RPM, which I can't explain.

In this context, I've had another idea related to the "Hoppeltest" (a diagnostic test). If the values displayed in VAG-COM MWB13 can always be used as a measure of the difference in acceleration between the cylinders, then it should also be possible to detect differences in compression between the cylinders by having the vehicle roll down a suitable inclined surface in drive mode.
Ideally, the incline and gear selection should be chosen so that the engine speed is only slightly above idle speed.
What do you think of this theory?

Regards,
Alex icon_confused.gif
AUDI A3 1.9 TDI, EZ 12/96, ursprüglich MKB AGR, umgebaut zum AHF mit GT1749V-Lader, verkauft mit 250tkm

Golf 4 1.9 TDI, EZ 1/98, MKB ALH, jetzt auch mit GT1749V-Lader, verkauft mit 300tkm

Touran 1.9 TDI, EZ 09/2004

Audi A4 Avant 2.0 TDI, EZ 03/2010


Translated on 20-09-2026, 13:36.
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