Audi PD TDI misfire

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Greg.H
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Audi PD TDI misfire

Post by Greg.H »

Hi all
I having a problem with 2006 Audi 2.0 PD TDI
Vehicle came to me after injector wireing loom been replaced but misfire is still present
Runs on limp home mode all the time.No trouble code in memory
Starts up all right and runs fine till warms up.when it's warm misfire very badly with loud diesel knocking noise.
So far what i've done.checked injector resistance at cold and hot engine.all same across the bord.
Cam&crank are fine.relative compression test shows up equal.
I did try to upload captured waveform but can't do it for some reason.
Basicly when it's cold one injector shows discrepancy and when it warms up have multiple injection signal issue

Greg.H
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Re: Audi PD TDI misfire

Post by Greg.H »

Why does it says board attachment quota has been reached??

Martyn
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Re: Audi PD TDI misfire

Post by Martyn »

I have upped the available space so it should be good for an upload now.
Martyn
Technical Support Manager

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Robski
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Re: Audi PD TDI misfire

Post by Robski »

No trouble code in memory
What scan tool ?

What do the MVB's reveal ?

LP & Tandem pressures/air free, injectors set correctly, fuel quality ?
Runs on limp home mode all the time
Starts up all right and runs fine till warms up
confused ?? :?

Lots of things to test & lots of info in MVB's !

Greg.H
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Re: Audi PD TDI misfire

Post by Greg.H »

Warm engine misfire
Attachments
warm engine start up with misfire.psdata
(3.09 MiB) Downloaded 719 times

Greg.H
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Re: Audi PD TDI misfire

Post by Greg.H »

Thanks Martin
So what's that MVB stand for?
I ment to say starts up without misfire and runs smooth till warms up and begin the funky style.
There is no time when the car has a full power and wont go over 3000Rpm
Scan tool is VCDS
1 bar pressure at KOEO and 3.5 bar with engine running.i can't see any air bubble in clear fuel pipe

Greg.H
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Re: Audi PD TDI misfire

Post by Greg.H »

Cam&crank cold start up
Attachments
Cam&Crank(cold start up).psdata
(7.17 MiB) Downloaded 659 times

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Robski
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Re: Audi PD TDI misfire

Post by Robski »

Greg.H wrote:Thanks Martin
So what's that MVB stand for? Measured Value Block
I ment to say starts up without misfire and runs smooth till warms up and begin the funky style.
There is no time when the car has a full power and wont go over 3000Rpm So never full power ? you're hard to understand :?
Scan tool is VCDS So you should know what MVB is, what version is it ?
1 bar pressure at KOEO and 3.5 bar with engine running.i can't see any air bubble in clear fuel pipe Tandem pump pressure I presume ? Is that 3.5 Bar max ?
What's the engine code of this thing ?

PS
There is a 'NOTES' tab that brings up a box you can type in & say where you're probed etc, use it !!!

Greg.H
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Re: Audi PD TDI misfire

Post by Greg.H »

Sorry I don't normally post (i suppose you can see that :) ).Scanner is 908 with 2012update.
Right
I only looked MVB at cold start yet and looked fine.i'll look at warm engine value as well.
Car starts up straight away and runs on all 4 cylinder but even with the cold engine there is NO POWER.runs on limp home mode.once when it warms up starts the misfire .if i drive the car it smokes very badly and engine makes knocking noise.i does jerk up when it's driven.
Pressure is measure at the tandem pump.Peak pressure around 7 bar(needle fluctuate too much so i can't exactly tell)

KimAndersen
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Re: Audi PD TDI misfire

Post by KimAndersen »

Hi..

I'll ask the same question as Robski did - what's the engine code on this Audi !

Did you read measuring block values for air mass sensor ! I mean specified versus actual values from the air mass sensor.

Your scanner 908, does it show specified values as the software VCDS from Ross-Tech does if not then it´s real difficult to tell whether you are getting the right values.

Could you measure the signal from the air mass sensor and upload your result here !


Regards
Kim

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