Broken fuel injector pump?

Bei meinem A3 TDI 110PS hab ich vor drei Tagen einen plötzlichen Leistungsabfall auf der Autobahn bemerkt. Und zwar reagierte er auf das Gaspedal so gut wie gar nicht mehr, bei ca. 120km/h war dann Schluss. Beschleunigung so gut wie keine. Nach ein paar hundert Meter war das Ganze dann plötzlich wieder vorbei und ich hatte wieder die volle Leistung. Am Tag darauf hatte ich wärend eines Überholvorgangen kurzzeitig wieder das Problem. Als ich mich dann abends auf den Heimweg machte war die geringe Leistung sofort nach dem Starten vorhanden. Außerdem hört sich der Motor beim hochdrehen an wie ein kalter Traktor. Nagelt wie verrückt, jedoch keine ungewöhnliche Rußentwicklung. Laut "My specialist workshop reports the following error code: '0550 Injection start control, difference from target value'.""He plugged in the diagnostic tool, and it indicated that the fuel injection pump needed to be replaced."
My question to you experts is whether the problem might be solved by replacing the timing belt tensioner? Or are there any other options besides replacing the pump (which costs about €1500 including installation!), and how can I easily check this?

Hello,

If the engine is making a loud, knocking noise, it's likely that the fuel injection timing is too early.
Possible causes include:
- a cable or connector defect affecting the spray nozzle adjuster.
- faulty fuel injector.
- defects in the timing belt tensioner (insufficient tension).
- Loose timing belt sprocket.
- faulty fuel injection pump.

Before you replace the most expensive part, the fuel injection pump, you should be 100% certain that nothing else is causing the problem.

Best regards, Rainer.

Error code: 550
Injection start control, pressure differential.

Possible causes:
Fuel injection start valve (N108) is defective.
Needle feed mechanism (G80) malfunction.
Fuel tank emptied.
Fuel supply not working correctly.
Fuel shortage.
Air in the fuel system.
Funding start not OK.
Fuel filter clogged.
Fuel lines with leaks.

Otherwise, take a look at this topic (a search will help), as it turned out to be just a cable in that case.
/viewtopic.php?t=3462&highlight=spritzbeginnregelung

Hi,

I had the same problems, or rather, the same error message as you. I can only agree with the suggestions mentioned above. Ultimately, in my case, it was the following:

'The fuel injection adjustment was not working, despite a perfectly functioning fuel injection adjustment solenoid valve, flawless cable connections, and sensors. The injection timing was essentially fixed at an extremely advanced setting (which caused the knocking). Ultimately, the fuel injection pump was replaced, and then everything was working properly again.'

According to the workshop, corrosion and deposits have formed in the ESP (Exhaust Gas Recirculation system), which has affected the adjustment mechanism for the injection timing. The cause of the deposits/corrosion is biodiesel.

While VAG allows the use of biodiesel in their vehicles, Bosch does not approve the use of their pumps for it... well, that's the situation.

In such a case, next time before replacing the pump, I would perform an 'intensive cleaning' of the pump using a diesel system cleaner to get it working properly again. Apparently, this has worked in the past... or so they say.

Regards,

Spocht.

This is damage caused by biodiesel.

Sure, here is the translation of the text from German to English:

'Cu Gremlin'

Deleted as requested.

What was the exact cause of the damage? Biodiesel itself doesn't typically cause a rupture on the pressure side of the SV (safety valve) piston.

corrosion (which is clearly visible in the upper area), leading to material fatigue and fracture. As a result, the piston is damaged...

CU Gremlin.

Bei meinem A3 TDI 110PS hab ich vor drei Tagen einen plötzlichen Leistungsabfall auf der Autobahn bemerkt. Und zwar reagierte er auf das Gaspedal so gut wie gar nicht mehr, bei ca. 120km/h war dann Schluss. Beschleunigung so gut wie keine. Nach ein paar hundert Meter war das Ganze dann plötzlich wieder vorbei und ich hatte wieder die volle Leistung. Am Tag darauf hatte ich wärend eines Überholvorgangen kurzzeitig wieder das Problem. Als ich mich dann abends auf den Heimweg machte war die geringe Leistung sofort nach dem Starten vorhanden. Außerdem hört sich der Motor beim hochdrehen an wie ein kalter Traktor. Nagelt wie verrückt, jedoch keine ungewöhnliche Rußentwicklung. Laut 'According to my specialist workshop's diagnostic report, the error code '0550' indicates a problem with the injection start control.''Geldifferenz' was stored in the error memory, indicating that the fuel injection pump would need to be replaced.
My question to you experts is whether the problem can be solved by replacing the timing belt tensioner? Or are there any other options besides replacing the pump (which costs about €1500 including installation!), and how can I check this most easily? }

Hello,
'I had the exact same problem with my G3 back then. It initially happened during full-throttle driving, and later also after starting the engine. The cause was a clogged diesel filter, which allowed air to be sucked in (at the T-piece on the filter). After replacing the filter, everything was okay again.'
Are there air bubbles traveling through the transparent hose connected to the ESP? And are there particularly many bubbles when you accelerate? If so, I suspect the filter is the problem.
This also aligns with the error log. The pump is supplying or compressing air, which prevents the amount of fuel injection that the control unit expects based on the needle lift sensor signal. As a result, the control unit attempts to adjust the fuel injection, but these adjustments quickly reach a limit and cause the error log to be generated.

I hope I was able to help.

Greetings.

Eike.

Old thread, but always relevant:

After experiencing the exact same symptoms (in my case, it wasn't related to overtaking), I initially replaced the "forgotten" diesel filter after approximately 70,000 km. The old filter was still somewhat passable when tested, and there was no air in the line. In addition, I used an expensive fuel system cleaner, initially with no success whatsoever.

My car, after about 30 km of driving at its maximum speed of approximately 100 km/h, was still completely unresponsive and absolutely refused to adjust the fuel injection timing.

I've already checked my account balance, looked online for used pumps, found the part number, and now I'm going to proceed with the final check as described above, so I can then purchase and replace the pump.

On my last trip (it was revving like crazy, which sounds really weird), the tension finally eased. After one of the many resets, just to get up the next hill with more than 50 km/h, my diesel engine suddenly shot forward like a ground-to-air missile. At least, that's what it felt like after 3 days of driving very cautiously .

He's driving smoothly, and the engine is running cleanly, handling all the changes in RPM and load without any complaints. Hopefully, it stays that way...

Data:

Engine: AHF - 110 HP with chip tuning, 200,000 km. Approximately 1-2 years were spent unknowingly running the engine with 20-30% biodiesel in the tank. For at least 3 years, only regular gasoline has been used, and recently, more often the expensive premium gasoline (because you have to treat it well sometimes...).

Best regards,
Uwe