VW Jetta Juddering when engine under load after miss-fuelling

[r.a]

Hello everyone. In need of help trying to diagnose a fault after miss fuelling 2006 Jetta 1.9TDi.

Mistakenly filled up with £30 worth of unleaded and drove down the road, car started coughing and spluttering and then cut out before I noticed my mistake.
Car was recovered, drained, flushed through with some diesel and had fuel filter replaced. It was driving fine but on two occasions afterwards I stupidly let the fuel level get low (1/4 tank) and engine stopped on both occasions. Engine restarted fine after filling up diesel. The problem is that since miss fuelling, the car now judders and vibrates when under load in higher gears (4th & 5th). i.e when travelling up hill or foot down on accelerator doing 60mph+

Have code read the car and nothing comes up. I Have used a few doses of Millers and Wynns fuel addictive/system cleaner and the Wynns seemed to have relived the symptoms slightly for a while. After speaking to others I think that the fault could lie with the in-tank fuel pump potentially?

Any of your thoughts / ideas would be greatly appreciated as this problem is driving me a bit nuts now.

Thanks in advance.

[Guest 2]

Welcome.

What was the car scanned with?

[r.a]

OBD scanner

[Guest 2]

Where are you in London, ideally the car needs scanned with VCDS.

[r.a]

Car is located in North Yorkshire at the moment.

[r.a]

Would VCDS highlight injector/fuel pump fault?

[Sam]

I think you've got a 55 litre tank. With diesel at an average of 137ppl, £30 is about 20/23 litres which is well over what you could have safely got away with (25% ish max).

First mistake was driving it, but it's too late to fix that now.

Second mistake was letting the fuel get so low, but it's too late to fix that now too(!)

At the very minimum you're looking at a new fuel pump and injectors with the potential for needing new fuel lines/seals/etc

[r.a]

I was hoping that it wouldn't be injectors, as this would probably be an uneconomical repair.

Would I be correct in thinking that VCDS would identify faulty injector(s).

[Guest 2]

Yes, VCDS will show this if thats the case.