VCDS graph - what is wrong

[pinstripe]

Can anyone help me read this graph (attached) or where is obvious to start looking for a problem

to me it seams it could be N75? but i am not sure or maybe some air leak somewhere - but cant really hear it.

tdi 1.9, 115hp, 2007

 

Group 11

or here are full figures

 

RPM  Abs.Pres Abs.Pres.A Duty Cycle  %
1491    1162,8    1040,4    72,6
1491    1183,2    1050,6    71,4
1512    1213,8    1071    69,8
1554    1866,6    1091,4    80,5
1533    1866,6    1122    80,1
1554    1887    1183,2    80,1
1575    1897,2    1264,8    80,1
1596    1907,4    1346,4    79,7
1638    1938    1428    79,7
1659    1958,4    1519,8    76,1
1680    1968,6    1601,4    67,5
1722    1999,2    1693,2    58
1743    2019,6    1805,4    51,3
1785    2019,6    1907,4    46,6
1806    2029,8    2009,4    43,4
1869    2029,8    2091    40,6
1890    2040    2162,4    35,9
1932    2040    2233,8    32
1974    2040    2233,8    32,4
2016    2040    2131,8    42,2
2058    2040    2029,8    45,4
2100    2040    1948,2    46,9
2121    2040    1887    48,1
2163    2040    1856,4    48,5
2205    2040    1836    48,9
2247    2040    1846,2    48,1
2289    2040    1856,4    46,9
2310    2040    1876,8    46,2
2352    2040    1897,2    45,4
2394    2040    1927,8    44,2
2436    2040    1958,4    43,4
2478    2040    1989    42,2
2520    2040    2029,8    41
2541    2040    2060,4    40,2
2583    2040    2091    38,7
2625    2040    2121,6    37,5
2667    2040    2152,2    35,1
2709    2040    2172,6    33,5
2730    2040    2182,8    32,4
2772    2040    2182,8    32,4
2814    2040    2172,6    33,1
2856    2040    2152,2    33,9
2898    2040    2111,4    36,3
2919    2040    2080,8    36,7
2961    2040    2040    37,5
2982    2040    2009,4    37,9
3024    2040    1989    37,9
3066    2040    1989    37,5
3108    2040    1989    37,1
3129    2040    1999,2    37,1
3171    2040    2009,4    36,7
3192    2040    2019,6    36,3
3234    2040    2029,8    35,9
3276    2040    2029,8    35,9
3297    2040    2029,8    35,9
3339    2040    2029,8    35,5
3360    2040    2029,8    35,5
3402    2040    2029,8    35,5
3423    2040    2029,8    35,1
3465    2040    2029,8    34,7
3486    2040    2029,8    34,7
3507    2040    2040    34,3
3549    2040    2040    34,3
3570    2040    2040    33,9
3612    2040    2040    33,9
3633    2040    2040    33,9
3654    2040    2040    33,5
3696    2040    2029,8    33,5
3717    2040    2029,8    33,1
3738    2040    2029,8    33,1
3780    2040    2029,8    32,7
3801    2040    2029,8    32,7
3843    2040    2029,8    32,4
3864    2040    2029,8    32,4
3906    2040    2040    32
3927    2040    2040    31,6
3948    2040    2040    31,6
3969    2040    2029,8    32

 

Edited 25 May, 2016 by pinstripe

[pinstripe]

and here is group 10 if it is of any additional help

graph in att.

MassAir Abs.Pres.Abs.Pres.  Load
250    989,4    1009,8    16,1
330    989,4    999,6    25,1
435    989,4    999,6    29,8
460    989,4    1030,2    52,2
515    989,4    1060,8    100
540    989,4    1111,8    100
570    989,4    1173    100
600    989,4    1224    100
645    989,4    1295,4    99,2
680    989,4    1366,8    97,6
730    989,4    1448,4    97,6
760    989,4    1530    98
840    989,4    1611,6    98
900    989,4    1703,4    98
965    989,4    1815,6    98,4
1000    989,4    1917,6    100
1030    989,4    2009,4    100
1075    989,4    2091    100
1095    989,4    2172,6    100
1040    989,4    2213,4    100
915    989,4    2142    100
880    989,4    2040    100
880    989,4    1968,6    100
885    989,4    1917,6    100
895    989,4    1887    100
885    989,4    1876,8    100
895    989,4    1876,8    100
905    989,4    1887    100
935    989,4    1897,2    100
930    989,4    1927,8    100
940    989,4    1948,2    100
955    989,4    1968,6    100
960    989,4    1999,2    100
975    989,4    2029,8    100
995    989,4    2060,4    100
1010    989,4    2101,2    100
1010    989,4    2131,8    100
1020    989,4    2162,4    100
1025    989,4    2182,8    100
1015    989,4    2193    100
1000    989,4    2172,6    100
980    989,4    2152,2    100
955    989,4    2111,4    100
935    989,4    2070,6    100
915    989,4    2029,8    100
915    989,4    2009,4    100
915    989,4    1999,2    100
910    989,4    1999,2    100
925    989,4    2009,4    100
920    989,4    2019,6    100
930    989,4    2029,8    100
935    989,4    2029,8    100
930    989,4    2040    100
940    989,4    2040    100
940    989,4    2050,2    100
940    989,4    2050,2    100
935    989,4    2050,2    100
930    989,4    2050,2    100
925    989,4    2050,2    100
925    989,4    2050,2    100
930    989,4    2050,2    100
910    989,4    2050,2    100
920    989,4    2040    100
915    989,4    2040    100
915    989,4    2040    100
915    989,4    2040    100
910    989,4    2040    100
915    989,4    2040    100
905    989,4    2040    100
905    989,4    2040    100
910    989,4    2029,8    100
910    989,4    2029,8    100
905    989,4    2029,8    100
900    989,4    2029,8    100
900    989,4    2029,8    100
915    989,4    2029,8    100
910    989,4    2029,8    100
895    989,4    2029,8    100
900    989,4    2029,8    100
895    989,4    2029,8    100

[pinstripe]

I just did the check of all hoses (from turbo to intercooler and from it, as well as from airbox to turbo) and all lines from N75. I did a good check (taken hoses out or from underneath and from above - i used a mirror too, so i could view it from all angles. Officialy, i can report there is no leak all are in perfect condition. What i didn't do is pressure test - i don't have the pump or right tool to do it.
Based on graph - do you believe it is N75 that can malfunction in such a way? or how to test it?
Maybe any other possibilities?
Thanks in advance.

[pinstripe]

Ok...further. Just checked the check valve ( the small black & white cylindrical device) and is working properly (can blow from one side but blocks from other side)

Cleaned the boost pressure sensor (although, i don't get any errors when scanned with VCDS)

I checked the actuator rod as well - it is moving as it should. There are no strange noises from turbo.

still no changes...


just to add to my 1st post - i get sluggish acceleration (can be seen from a graph) and more black smoke


still open to ideas
 

Edited 27 May, 2016 by pinstripe

[0wl]

Lots of black smoke means the mix is too rich, either not enough air/oxygen or too much diesel.

Have a look at this page and follow the guidance:

https://sites.google.com/site/1810martin/vcds-and-pd-tdi-engine-health-check

Prior to performing the above checks note what is mentioned about ensuring the air filter and fuel filter are ok / fitting new ones.

The coolant temperature sensor is a common failure point that would result in overfueling and it doesn't usually flag a fault code.

Edited 27 May, 2016 by 0wl

[pinstripe]

0wl thanks for pointers.

Yesterday i did a vacuum leak test ...and i got hiss from the oil dipstick - it is not cracked it just has a play of some 2-3 mm.

Do you believe that this might contribute to issue i have. - or is this normal?

As i could learn the dipstick does not have something like an O-ring (in case i buy and fit a new one) do you believe it would be a tight fit? Or i just take it off and put some loctite seal on it (i am just scared that it might brake in process of taking it off)?

thanks

[pinstripe]

Further....

I had replaced the funnel (plastic tube) and it is 4/5 better ...but there is still some hisss (but nothing to worry about) due to the perfect engineering of VW - there is no O-ring where the tube is connected to metal.

i have checked the turbo too. I have taken off the rubber hose going to turbo and inspected the impeller and bearing for any play - but everything seams to be in perfect order. There is even almost no oil in the hose. Just enough to make your finger dirty.

 

So, with no more air in the cooling system and heater matrix, no vacuum leak, nothing wrong with the turbo and actuator rod in working order, i am still wondering why there is still

- excessive black smoke present

- no pressure in the cooling system

- not smooth running at 1100 1800-1900 and around 2500-2700 rpm

 

EDIT:

I sorted it somehow - but:

 

in VCDS the group 04
KW was between -2,5 to -2,9 and even jumped to -3,4 one time

 

i did the injection timing (clockwise) and is now 0.0

i get more bottom power and less vibration -though still presnet

i would increase it to 1.0 but there is no more room - bolts are on the and of the line + my tooth belt is now on the inner edge

how to fix this?

 

[rotodiesel]

The cambelt is out of position by one tooth. The range of adjustment on the slotted holes slightly exceeds one tooth pitch - so you can always set KW correctly and have some adjustment.

 

The belt is axially guided by the flanges on the tensioner wheel. If it's not fraying at the edge there is no problem, but if it is, something is out of square or not properly seated.

 

rotodiesel.

[pinstripe]

The cambelt is out of position by one tooth. The range of adjustment on the slotted holes slightly exceeds one tooth pitch - so you can always set KW correctly and have some adjustment.

 

thank you rotodiesel.

can you put me in direction of how to set KW correctly while i have it in this position? As i can see,  i can go only counterclockwise - but with this approach i would again put it to retarded timing...or i am not taking everything into consideration... ?

[rotodiesel]

The way to set KW is to use the correct locking tools when changing the cambelt, positioning the belt so that as it is tensioned, the bolts are somewhere within the range of the slots. They certainly don't need to be central and often are not.

 

When my Superb was new the bolts were at one end of the slots. When I changed the belt, I decided to position it such that the bolts are now near the other end - ie. the belt is moved one tooth. I chose this position to give me more latitude in the KW setting.

 

The car ran perfectly as delivered and still runs perfectly after my belt change (40k miles ago) and in each case, KW was near zero. You need VCDS or equivalent to check KW unless you use a 2 channel oscilloscope on the crank and cam position transducers.

 

After fitting the belt, KW can be trimmed to zero in-situ by removing the upper belt cover. In practice, if you use the locking tools carefully, KW is nearly always within the allowed tolerance without further adjustment.

 

If you can't get KW = zero with your belt as positioned, you need to take it all apart and move it round one tooth - using the proper locking tools.

 

rotodiesel.

Edited 3 August, 2016 by rotodiesel

[pinstripe]

rotodiesel many thanks for this explanation

i have VCDS and KW was -2.5 and in driving jumped on some rpm on -2.9 and back to -2.5

i did the adjusting (loosen the 3 bolts on the cam sprocket and moved the big bolt clockwise-just a hairline)

i checked again and it was dead 0.0 - while driving on some rpm goes to -0.5 and back to 0.0

i got more bottom power but i think it is now less fuel efficient.

 

after this adjustment the belt moved more to inner edge as it can be seen from pics

and what i noticed just now - the toothed window is not on the top but is now completely on the west side - is this how it should be or is now something seriously wrong?

it starts and runs normaly..

[rotodiesel]

If KW is zero there's nothing wrong as long as the belt is not being damaged by running on one edge. On my PD and nearly all of the many others I have examined, the belt runs almost dead centrally on the cam pulley - so you might need to keep a watch on it. Watch particularly the stepped stud for the tensioner - which is under engineered and will not withstand repeated tightening of the nut to its specified torque.

 

The toothed window rotates with the camwheel. When the engine is pegged at TDC, the toothed window is pretty well at the top. If your engine runs properly, it can't be wrong.

 

rotodiesel. 

[pinstripe]

hey rotodiesel

you are 100% correct;

stupid of me - the toothed window rotates and it can be on one spot - disregard this statement please.

i had gone and immediately checked the tensioner  (look at the pic);  it is way of i would say...

i could bet, this might be the reason for poor alignment of tooth belt.

You already answered my next question - can i adjust it ? can i try? or i am pushing my luck?

and if, do i need to have the locking tools for this action?

 

My thought is; untight it just as much to re-align the toothbelt and then tight it back to the spec. torque. ?

 

[rotodiesel]

You can't adjust the tensioner without pulling the front, installing the locking tools and slackening the 3 camwheel bolts. This is because without the locking tools, the engine has locked-in torque due to the action of the valve springs and the return springs in the unit injectors. The locked-in torque tends to rotate the camshaft relative to the crank and give the wrong tension. When setting, the tension must be provided only by the torsion spring inside the Litens tensioner. This is one reason why the camwheel can rotate relative to its hub when unlocked. The other reason is, of course to get the timing dead right.

 

Note also that the belt tension setting is very temperature dependent - engines expand when hot and the drive centres move apart. Set the tension when stone cold, with the belt and the engine at the same temperature.

 

Bodging these engines (often a dealer speciality, complete with white paint) usually ends in grief. Using the right tools is much quicker anyway.

 

rotodiesel.

[pinstripe]

OK guys - thanks for the inputs

this topic is considered SOLVED - leaning on the topic

http://www.briskoda.net/forums/topic/407998-timing-belt-tensioner-moves-while-rotating-the-crankshaft/