2005 2.0 TDi PD sportline

[AUDICAB99]

Hi,

Wondered if any of the tech guys out there could gimme some help..

Car is a 2005 A4 avant 2.0 TDi Sportline..

Problem is....Car has absolutely no power whatsoever,to the point the car will more or less stall when pulling away.Will rev slowly through the rev band,but it is extremely sluggish. If you pull up,the car will rev freely,but again doesnt rev as quickly as it should.

New parts that have been fitted....


Turbo boost pressure sensor..
Mass air flow sensor
Throttle body housing with motor.
Turbo actuator solonoid.

All parts are genuine OEM..

Additional things that have been checked..

Exhaust for any blockages....Checked out fine..
Turbo...Was removed and inspected...All fine..
All turbo hoses for splits or cracks.......All fine
Valve timing checked.................All fine
Injectors checked and readjusted...All fine.

Major problem is that there is never any fault codes in the car,and never has been.Although its blatantly obvious the car is far from correct..

Fault codes are being checked with VCDS VAGCOM..

Just a little history,although im not sure of its relevance.The car had a recon engine 20k ago due to oil pump packing up and damaging the engine beyond repair.
Ran fine since recently..:(

Desperate for fresh idea's is an understatement..:aargh4::aargh4::aargh4:

Any help appreciated

[sr-performance]

Hi mate,
As you haven't got it on your list have you had the intercooler checked?

[AUDICAB99]

It has been checked with a smoke tester to make sure there were no leaks..

I guess that doesnt check if its blocked ??

Is there any common issues with the intercooler ??

Thanks for the help BTW...:beerchug:

[a8 tech]

If there no codes then intercooler etc will be ok as you would see underboost or overboost for turbo sticking or vacuum/intake leaks.
Ok you need to start looking at the injectors and the head, check the tandem pump pressure under load and also check the delivery rate from the fuel tank pressure pump.If you have insufficient fuelling then torque will be reduced.


Fuel pressure is the key to this sort of issue with the pd engine and if the tandem pump receives insufficient volume then so do the injectors so establish the quantity by disconnecting the fuel input at the tandem and crank for 10 seconds, you should see approx 450ml.

Check the fuel pressure at the pump for drain off from injectors partially opening or cracked internal cylinder head fuel ports.

Remove the fuel filter and empty it into a clear container and look out for oil, if oil is present go to the fuel tank and remove the fuel pump and if there is oil present then thats the fault (leaking tandem pump allowing fuel and oil to mix causing poor combustion and reduced power)

[sr-performance]

I would find your local delphi diesel specialist mate, they very good at finding probs like yours....

[AUDICAB99]

Hi A8 Tech...

I was hoping you would reply...;)

Do you know what values pump delivery rate and loaded pump pressure should be by any chance ?

When you say "start lookin at injectors and head",do you mean measured values of the injectors ?

What issue could the head have to cause this fault ???

Again,thanks for your time and help on this issue :)


Ah....see you answered some of my Q's in your edit..:)

[a8 tech]

The head cracks but start with the suggested oil contamination of the fuel system.
I have added the mvb on the forum for B7 in the past but will look them up again.
Make the job easier and establish the condition of the fuel filter firstly then I will try to guide you further.
Regards A8

[a8 tech]

Do you know your engine code by chance

[AUDICAB99]

Sorry..

I dont off the top of my head....But will update with the info first thing in the morning :)

Just for info,does the PD have some kind of fuel monitering device(or knock control sensor) that reduces torque and performance if the fuel condition deteriorates ??

The PD sems a complex thing to fix..:(

[a8 tech]

Unfortunately it does not and that's part of the puzzle as the injectors increase the pressure via ecu duty cycle commands which are practically un checkable even if you scope them.Is this a 170 or 140 bhp

[AUDICAB99]

Does engine code BDB sound correct ?? Will double check that one..

So..........

If oil leaks through the tandem pump,will it drop the actual fuel pressure to the injectors ?

Or is it because there is oil in the fuel that causes the injector to incorrectly compress the fuel/oil/mixture causing low pressure??

Sorry for all the questions by the way,just trying to get my head around how it works!!

[a8 tech]

When the fuel and oil mix its just like using poor quality fuel and as the combuston prcoss is critical then it suggest poor combustion occurs from the contamination.
Ok lets look at mvb's

018 Status of pump/nozzle unit piezo valves
1) Cylinder 1
2) Cylinder 2
3) Cylinder 3
4) Cylinder 4
Key - cylinders 1 to 4:
000 Fault-free control
002 Closed-loop control at start
004 Small injection quantity or piezo valve off
008 Energy limits reached
016 Valve closing time implausible
032 Piezo capacity implausible
064 Piezo energy implausible
128 No closing time identification possible (poss. elec.fault
in measuring channel)

023 Closing times of pump/nozzle unit piezo valves
1) Cylinder 1
2) Cylinder 2
3) Cylinder 3
4) Cylinder 4
Values, cylinders 1 to 4: 0.18 ... 0.25 ms

008 Limiting torques 1
Coolant temperature min. 75°C:
1) Engine speed
At idle: 870 ... 890 rpm
At full throttle: 2800 ... 3200 rpm
2) Driver input torque (accelerator)
At idle: -5 ... 0 Nm
At full throttle: 350 ... 450 Nm
3) Torque limitation
At idle: 150 ... 300 Nm
At full throttle: 350 ... 400 Nm
4) Smoke limitation
At idle: 100 ... 230 Nm
At full throttle: >= Torque limitation (see zone 3)

011 Charge pressure control
Coolant temperature min. 75°C:
1) Engine speed
At idle: 870 ... 890 rpm
At full throttle: 2800 ... 3200 rpm
2) Specified charge pressure
At idle: 900 ... 1150 mbar
At full throttle: 2100 ... 2600 mbar
3) Actual charge pressure (altitude and weather dependent)
At idle: 900 ... 1150 mbar
At full throttle: 2000 ... 2800 mbar
4) Charge pressure limitation duty cycle
At idle: 40...95 %
At full throttle: 15...95 %

013 Smooth running control
Measured values at idle after approx. 15 s, coolant temperature min. 75°C:
1) Injection quantity variation cylinder 1 [mg/stroke]
2) Injection quantity variation cylinder 2 [mg/stroke]
3) Injection quantity variation cylinder 3 [mg/stroke]
4) Injection quantity variation cylinder 4 [mg/stroke]

Note: To specify the permissible limits, the
current injection quantity must first be determined from measured value block 001 zone 2.
* The table below then shows
the permissible values for the idling speed smooth running control injection quantity.
* If the injection quantities listed
in MVB 001/2 at idle are not reached,
consumers should be switched on as necessary.

Injection volume Limits of injection
from MVB 001/2 quantity cyl X
5 mg/stroke -1.90 ... 1.90 mg/stroke
5,5 mg/stroke -2.09 ... 2.09 mg/stroke
6 mg/stroke -2.28 ... 2.28 mg/stroke
6,5 mg/stroke -2.47 ... 2.47 mg/stroke
7 mg/stroke -2.66 ... 2.66 mg/stroke
7,5 mg/stroke -2.85 ... 2.85 mg/stroke
8 mg/stroke -3.04 ... 3.04 mg/stroke
8,5 mg/stroke -3.23 ... 3.23 mg/stroke
9 mg/stroke -3.42 ... 3.42 mg/stroke
9,5 mg/stroke -3.61 ... 3.61 mg/stroke
10 mg/stroke -3.80 ... 3.80 mg/stroke


001 Injection quantity
Coolant temperature min. 75°C:
1) Engine speed
At idle: 870 ... 890 rpm
At full throttle: 2800 ... 3200 rpm
2) Injection quantity
At idle: 3.0 ... 10.0 mg/stroke
At full throttle: 45 ... 75 mg/stroke
3) Specified duration of delivery
At idle: 3 ... 9 °CA
At full throttle: 20 ... 30 °CA
4) Coolant temperature
Less than 75°C: => Warm up engine

[AUDICAB99]

Thanks for that table of MVB's..

Will have some more info and hopefully some MVB values to post up later..

Will keep you informed...

Many thanks for the help.....:beerchug:


One thing i did forget to mention in the OP,again not sure if relevant.There is absolutely zero exhaust smoke from the car when idling or when the RPM's are increased.

Would have expected to see something ???

[AUDICAB99]

Hi again...

Ok,

Removed the fuel filter and inspected diesel.. The fuel did look rather "dark" in comparison to normal diesel.Although it didnt look like it had oil or globules floating..

Anyway,removed all the fuel from the tank and put fresh diesel in just in case the original stuff was contaminated in some way..

Checked flow rate from the tank in the pump upto the tandem pump...650ml after 10 secs.. All ok....

Found a check procedure for testing tandem pump pressure on Elsawin..

Check Tandem pump pressure.........All ok...

Thats where were upto at the moment,will try and post up some MVB's when we next get on it..:(

[a8 tech]

The tandem pump test is only good for a staionary vehicle at 4000 rpm.Tip if you drive the car and watch the needle it will bounce like mad if the pressure drops off.

[a8 tech]

Vehicles with impaired performance but without any event memory entry:

Check air filter and boost pressure system (seal)

Check boost pressure sensor and accelerator pedal to make sure values are plausible

Data block 10: Check boost pressure sensor against the atmospheric pressure sensor of the engine control unit

(must be less than 50 mbar difference )

Data block 2: 99-100% has to be achieved in the pedal movement sensor test, when the accelerator is slowly depressed.

.

Basic setting, exhaust return valve and boost pressure controller:

Basic setting 03: Check exhaust return valve

Basic setting 11: Check boost pressure of exhaust turbocharger. Check vacuum control unit (ATL) with hand vacuum pump

if guide vane setting moves from 100 - 200 mbar, maximum setting is approx. 550 –650 mbar.

Check synchronisation angle

Data block 4/4: Check setpoint value +/- 3° for synchronisation angle/valve timing. If outside the tolerance, check valve timing and adjust.


If you do not notice any error, carry out a Lambda full load test

engine electronics / 011 measured values / display group 74

Engine coolant temperature over 75° C

Drive in 3rd or 4th gear, save under full load (100 % pedal
value) the measured value block 74 at least times at 3600 – 3800 rpm.

If the determined lambda value is > 1.38 then the injectors are blocked

[AUDICAB99]

Superb info....

Will check it out....

Thanks again for your time..Will report back with findings :)

[AUDICAB99]

Hello again mate..

Were slowly working through all the tests you have suggested.Upto now were having positive results and everything is in spec..

Just confused about the last piece of info you posted,specifically this...

"If you do not notice any error, carry out a Lambda full load test

engine electronics / 011 measured values / display group 74

Engine coolant temperature over 75° C

Drive in 3rd or 4th gear, save under full load (100 % pedal
value) the measured value block 74 at least times at 3600 – 3800 rpm.

If the determined lambda value is > 1.38 then the injectors are blocked"

On our VCDS, Engine electronics is 01,measure blocks is 08.011 is login

When in 01 engine,08 measuring block,MVB display group 74 is blank. There is no value..

Consequently were a little stuck and are unable to carry out any further testing,so we have stalled in trying to get the car sorted..

Is the any more advice you can offer us ????

[a8 tech]

Depending on engine code it may not support this operation

[AUDICAB99]

Ok....

Fair enough.....

Will carry on tommorow and see how we go.

[AUDICAB99]

Just to update this thread...

Needed 4 new injectors.....:aargh4::aargh4::aargh4:

£2000 and the car is running great again...

And that doesnt include previous parts fitted..:confused:

Think the major problem with diagnosis is that there is very little actual diagnostic output from the injectors.. Even when you suspect strongly that the injectors are at fault,its hard to be 100% positive..

[a8 tech]

Well done and as you now know the injectors have limited diagnostics but the pressure test shows some info regarding the opening sequence but not much more.Mvb are not much help either but if you have eliminated everything then its the last option.

[AUDICAB99]

Yes...

Thanks for your help by the way....

Very complicated that PD engine..

Sometimes i hark back to the GM 1.7 low blow turbo...ha ha