Random Cut Outs at junctions/low revs

[ChimpyPomPom]

Help! My beloved RCZ diesel has randomly started cutting out at junctions/low speeds. Its had a new alternator, and started doing this, as well as randomly struggling to maintain power for a millisecond, then recovering. Went in to the garage, was told a faulty fuel sensor, so was replaced and fuel filter changed and a system clean. No engine warning light has ever shown. And even more randomly, when it cuts out, nothing goes off on the dash, all lights/radio etc all still on. In fact, I don't even know its cut out. Never happens when going at speed, always when I'm slowing right down for a junction or traffic. Always restarts and pulls off without issue. Has run fine for last 3 weeks since sensor replaced, phoned garage this morning, and been told its because I've filled up at a supermarket with sub quality fuel.... Which I've always done, with no issues. Any ideas? Anyone?

 

[chrismac]

I hope you don't use the garage that said "sub-quality fuel" was the cause of your problems. They should not be in the Motoring business.

 

[diogosaka]

Had similar issues, Dealer wanted to push for a new ECU. As it was covered by a private warranty it was changed but the problem persisted.
It ended up being a botch job done on the cabling, hard as hell to find as you can imagine... No problem ever since