Apologies for the delay in getting an update posted on this. I recently had a problem with contaminated supermarket diesel (I kid you not) which took a bit of time to sort out.
Anyway, just before that incident - I finally got the juddering fixed! :icon_thumright:
I adjusted the intake cam to get the Torsion value to bang on 0.0kw.
The relationship between the front & rear cams had an effect on the
Engine Torque &
Fuel Consumption figures which are adjusted by the rear cam.
From what I've read - the ideal Fuel Consumption is around 0.6l/h & Engine Torque should be no less than 28 Nm.
*This is what I found has the most profound effect on the juddering after adjusting the Torsion value with the front cam.*
You can get away with a lower consumption on some engines - but for the BKD 0.6l/h seems to work best. Any less and you may get cold start problems and a bit of juddering - BUT - you will get improved MPG!
Note: This figure only changes in 0.2l/h increments. So, you can move the rear cam by a few degrees which keeps it at 0.6l/h but it still shows the effect on the "Engine Torque".
So, with the
Torsion value at 0.0 kw and this:
Group 015: Fuel Consumption
819 /min Engine Speed (G28)
30.0 Nm Engine Torque
0.6 l/h Fuel Consumption
0.0 Nm Torque Request (Driver)
... I was getting around 48 - 50MPG and a massive improvement in the juddering
However, I had read on another forum that some people have found that European engines seem to prefer negative torsion values.
So, as a last attempt to eliminate the juddering
altogether - I dropped torsion down to -1.5. And the juddering was totally GONE!
Now there is some info out there about a lower torsion affecting the torque curve as well as the MPG. To be honest I didn't get to prove this really because it was only a couple of days later before my car got poisoned .
However, part of the troubleshooting involved setting everything back to TDC which meant my timing is now:
Torsion: 0.0 kw
Group 015: Fuel Consumption
819 /min Engine Speed (G28)
28.0 Nm Engine Torque
0.4 l/h Fuel Consumption (it actually flicks between 0.4 to 0.6 l/h)
0.0 Nm Torque Request (Driver)
I have a lot of juddering now so I suspect I will have cold start problems when we get into winter here... but my MPG is great! I managed to get 60MPG a couple of days ago (driving like a granny at 70 in cruise for 75% of the journey) - but it was pretty good.
So, it seems a bit of a trade off. If I increase the Engine Torque & Consumption by a tiny bit more (rear cam > clockwise by a mm or 2) to get the previous figures of a steady 30 Nm & 0.6 l/h - I suspect my MPG will go down by about 4 or 5MPG. I think I'm going to have to do it though because the juddering is pretty annoying when idling.
Also, should mention that all adjustments should be done when car is at full temp. Also, measurements should be taken with all power consumers & air con off.
Sorry about the long post - just wanted to be thorough so hopefully someone else finds this useful!