Hello, my mk2 2012 octavia vrs tdi 170 had a problem a couple of weeks ago where the car started as normal and cut out 100 feet down the road. Almost stalled rather than cut out.

The car wouldn't restart and there was no codes when I scanned it. Came back to the car 6 hours later and started fine and ran fine. Checked the fuses and power supplies. In tank pump powered up, changed the fuel pump relay and replaced fuel filter.

Ran fine for a couple of weeks and then suddenly did the same thing this morning. Again 100 feet up the road and just cranks and won't restart.

Any ideas would be great as I'm getting a bit frustrated looking into this again!

If there are no codes stored then I reckon its maybe a fuel problem or perhaps imobilser kicking in? Could be the high pressure diesel pump. (electrical connection or pump failing). Try it without fuel cap in case vent is clogged and its causing a vaccum. If you don't have VCDS maybe get it scanned and see if it pings anything up that your scanner missed. Its weird its ok after leaving it for a while.

Alasdair

Just read on here that crankshaft speed/position sensor can be a cause with rarely a fault code

Extract from article

'The G28 sensors are known to suffer heat related failure and not to leave a code which makes them harder to diagnose. With the symptoms mentioned and especially the rev counter behaviour, it makes it certain for me without doing direct diagnosis such as logging the G28 signal. Also, the G28 is just about the only sensor that will cut an engine instantly if you disconnect it when running.'

I also read that the car wont start again until cool and it can affect the rev counter.

Alasdair

I will look into both of these thank you!