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Engine Misfire? Diagnose OK, but Performance Issues.

 
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sirecki
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Post09-06-2004, 23:34    Subject: Engine Misfire? Diagnose OK, but Performance Issues. Quote

Hi,

I'm experiencing a loss of power in the higher RPM range (I'm only reaching my top speed very slowly, around 180 km/h) and when the engine is cold, the car runs unevenly/erratically, which feels like misfires. Because there are no error codes stored, I've now read the values and unfortunately, I can't find anything unusual. Could someone take a look to see if I've missed anything? The data is as shown in the thread https://community.dieselschrauber.org/en/viewtopic.php?t=3322.
described, recorded, and, except for the fuel lines and filter, also checked off in sequence, and the idle speed control is also working correctly.
Oh yes, what I forgot to mention is that an oily liquid is leaking from the AGR valve, and could that much condensation accumulate in the hole directly below the 'plate'? I haven't looked at the AGR valve more closely yet, and my next step is to remove it and check for any buildup or contamination.
(AUY, 115 hp, direct injection, 6-speed)

I am sorry, but I am unable to access external websites or specific files online, including the PDF document you linked. Therefore, I cannot provide a translation of the text contained within that file.
I am sorry, but I am unable to access external websites or specific files online, including the PDF document you linked. Therefore, I cannot provide a translation of the text contained within that file.
I am sorry, but I am unable to access external websites or specific files online, including the PDF document you linked. Therefore, I cannot provide a translation of the text contained within that file.
I am sorry, but I am unable to access external websites or specific files online, including the PDF document you linked. Therefore, I cannot provide a translation of the text contained within that file.

Sure, here's the translation:

'Thank you in advance!'
Best regards, Ecki.


Translated on 20-09-2026, 15:32.
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Rudi
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Post10-06-2004, 8:20    Subject: Engine Problems: Misfire, Rough Idle, But Diagnostics OK? Quote

Hi,

... from the AGR valve, an oily liquid flows, or from the hole directly below the 'plate' .

Normally, nothing should flow there icon_exclaim.gif. It sounds like the valve might be damaged.

Please unscrew that part and put a solid copper gasket in between.

Best regards, Rudi.


Translated on 20-09-2026, 15:35.
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sirecki
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Post10-06-2004, 13:45    Subject: AGR Images: Photos & Pictures Quote

Hi,

I uploaded a few pictures online for clarification.

www.eg-media.de/daten/IMG_0509.JPG
www.eg-media.de/daten/IMG_0510.JPG
www.eg-media.de/daten/IMG_0517.JPG
It seems to be coming out of the borehole with such pressure that it's even making the valve cover damp.

Best regards, Ecki.


Translated on 20-09-2026, 15:36.
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ulf
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Post10-06-2004, 14:43    Subject: Engine Misfire? Diagnose OK, but Performance Issues. Quote

Hi,

The images suggest a leak between the intake manifold section and the diaphragm chamber.

"You can't really repair anything there normally, and even a blanking plate instead of a seal probably won't help."

I would probably replace the AGR unit icon_sad.gif.
Gruß Ulf
_________

MG4 Electric


Translated on 20-09-2026, 15:37.
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sirecki
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Post10-06-2004, 14:57    Subject: Root Cause Analysis: Problem Solving Guide Quote

Hi,

Is the defect the cause of my problems? And does anyone know if I can get this part as an accessory, or if it's recommended to buy it from there?
I just called PV Autoteile, and they said there's a pressure sensor, but it doesn't look like that when it's not assembled, and it doesn't seem like it can be detached from the main part. Has anyone had experience with this?
Apparently, Ford is planning to charge an extra 213 euros for it!

PS: Thanks, Ulf, for the quick information.
Best regards, Ecki.


Translated on 20-09-2026, 15:38.
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sirecki
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Post10-06-2004, 20:26    Subject: Removed valve: See photo Quote

Hi,

I removed the EGR valve, here are the photos of the valve.
www.eg-media.de/daten/IMG_0535.JPG
www.eg-media.de/daten/IMG_0536.JPG
Ich glaube das bei vollgas der Ladedruck teilweise aus den mit rotem Pfeil markierten Stellen ausweicht. Ich werde, da es wirklich nicht so aussieht dieses abdichten zu können, wie Ulf es auch sagte, ein neus AGR Ventil kaufen. Where exactly?
Ford: €213 plus shipping.
VW: €150, including.
and it doesn't seem to be available as an accessory. Are there any other options?

While the intake manifold is quite dirty, I don't think it's so bad that it would cause an air blockage. However, the individual channels for each cylinder might become constricted due to the level of dirt. To clean it, you probably have to remove it, right?
Can someone describe the amount of work involved and which parts will need to be replaced or purchased?

Best regards, Ecki.


Translated on 20-09-2026, 15:40.
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ulf
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Post10-06-2004, 20:36    Subject: Valve Removed: See Photo Quote

sirecki wrote:
While the intake manifold is quite dirty, in my opinion, it's not so bad that it would cause an air blockage. However, the individual channels per cylinder might become constricted due to the level of contamination. To clean it, you probably have to remove it, right?

Sure.
If I imagine the sludge in your EGR valve moving further towards the intake valves, I can already guess that the engine is probably not producing its normal power.
Possibly, the cylinder intake manifolds are clogged differently, which could also explain the rough idling: a cold engine plus reduced compression due to restricted airflow = misfires...?

Thank the creators of the emission standards: without EGR, you wouldn't be having this whole problem, in my opinion.

EDIT:
How many kilometers has the car been driven?

Slowly, I'm starting to suspect that, due to the large differences in EGR deposits in PD engines, a partially closed EGR valve, which doesn't cause problems in everyday use (yet) and is therefore often unnoticed, could, over the years, exhibit effects similar to those in your engine. icon_evil.gif
Gruß Ulf
_________

MG4 Electric


Translated on 20-09-2026, 15:43.
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sirecki
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Post13-06-2004, 14:17    Subject: Kilometer Performance: Mileage and Efficiency Quote

Hi Ulf,

The car has 160,000 kilometers of highway driving under its belt.

Best regards,


Translated on 20-09-2026, 15:45.
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sirecki
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Post13-06-2004, 23:14    Subject: New Information: Latest Updates & News Quote

Hi,

The intake manifold is only dirty on the part connected to the EGR valve. It's clean near the cylinder head, and there's only a slight oil film directly on the head. The EGR valve is now new, but deactivated, and the car runs better. However, at very high RPMs, the power still drops off, so the top speed is reached very slowly. Therefore, I recorded the values again during a test drive and revved the engine to its maximum limit.

www.eg-media.de/daten/LOG-01-001-009-008.pdf

During this process, I noticed that the actual fuel injection amount drops below the lowest 'target' value starting at approximately 3000 RPM, and the difference increases as the RPM increases.
Is that normal?

Best regards, Ecki.


Translated on 20-09-2026, 15:46.
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knubbi
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Post14-06-2004, 5:32    Subject: Engine Misfire? Diagnose OK, but Performance Issues. Quote

Hello!

Could you please do us a favor and prepare your log files a bit using Excel?

The data can be imported very easily.

You can't really do much with these data series.

Regards,

Knubbi.


Translated on 20-09-2026, 15:47.
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sirecki
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Post14-06-2004, 12:21    Subject: SEO: Best Practices for Website Optimization Quote

Sure, I'd be happy to. But I thought it would be more readable for more people if it were in PDF format. Of course, the raw data is better suited for editing the data.
www.eg-media.de/daten/LOG-01-001-009-008.xls

Best regards, Ecki.


Translated on 20-09-2026, 15:48.
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knubbi
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Post14-06-2004, 13:34    Subject: Engine Misfire? Diagnose OK, but Performance Issues. Quote

...and now, please provide a log file containing all blocks of the airflow path.


Translated on 20-09-2026, 15:49.
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ulf
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Post14-06-2004, 14:37    Subject: New Information: What's New? Quote

sirecki wrote:

During this process, I noticed that the actual fuel injection amount drops below the lowest "target" value starting at approximately 3000 RPM, and the difference increases as the RPM increases.
Is that normal?

Theoretically, probably not.

But if you look at the timestamps, you will see differences between the individual data packets in the same line.

So, there is no truly precise temporal relationship between the MWBs.
I believe the differences in limitations and quantities between MWB 1 are due to that.
Gruß Ulf
_________

MG4 Electric


Translated on 20-09-2026, 15:50.
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sirecki
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Post14-06-2004, 16:00    Subject: Engine Misfire? Diagnose OK, but Performance Issues. Quote

Actually, the timestamps are not the same, which explains the difference. Thanks for pointing that out!

@knubbi:
Are blocks 3 and 10 the ones being referred to?
www.eg-media.de/daten/LOG-01-003-010-001.xls

Best regards, ecki.


Translated on 20-09-2026, 15:51.
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PrivatBereich
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Post14-06-2004, 16:20    Subject: Engine Misfire? Diagnose OK, but Performance Issues. Quote

Are blocks 3 and 10 the ones you mean?

Okay, just change 10 to 11, and then we'll also see the desired pressure instead of the atmospheric pressure.

And if you want to be really good, then create one or more charts directly from the Excel data. That way, the person who is supposed to help you won't have to do it.

It's also important to occasionally include some segments where the engine is running at full throttle for a longer duration, exceeding the typical 5-7 data points. For example, running at 2000-4000 RPM in full throttle in 3rd or, ideally, 4th gear (be aware of the high speed, highway driving is recommended). Also, avoid logging unnecessary data blocks, as this will increase the sampling cycle (resulting in fewer data points from the important section per unit of time).

Regards,
Private.


Translated on 20-09-2026, 15:52.
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knubbi
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Post14-06-2004, 16:22    Subject: Engine Misfire? Diagnose OK, but Performance Issues. Quote

Sure, please provide the text you would like me to translate from German to English.


Translated on 20-09-2026, 15:53.
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