Or rather sparks out of the back box! Making 'steady progress' down the M3 tonight in my VW T4 LWB 2.5TDi, well loaded upwith people/crap/luggage etc, when I see that it seems to have got 'a bit hazy' behind me but not in front! Power was still fine and all guages in the green so to speak. Pulled over to the hard shoulder to have a gander, expecting the worst, but the engine was still ticking over fine with no nasty noises/flames etc. Had a look up the back while it was still running and saw a few sparks coming out of the back box! Switched off after a minute or two and checked all fluids. All fine. No leaks or signs of overheating. Admittedly I was giving it a bit of stick, but these ACV lumps are built to take it. I fitted a simple 'tuning' device sourced from Ebay about a year ago which intercepts the ECU analogue voltage output to the injection pump to increase the fuelling. This has proved excellent (until tonight). I disconnected it and continued the remaining 80 miles home with no problems or smoke for that matter, so hopefully no damage done. I was getting worried for a while there as it's booked in for MOT tomorrow at 10.15am! A quick check with VAG-COM tomorrow morning I think.
JB