hi not mark 3 but as same age thought id ask and recall symptoms when i used have mk3 and was on here, i got a prob comes and goes some time revs up and down between 1400 and 1700 it lurches and accelerate by itself at those revs, it can go away and only rev 1200 steady until warm then idel normally, it does feel slightest lumpy feel on idle still as to what used feel like. Sometimes goes away it varies over weeks between all three.
I had rac guy look as had battery being flat, he looked at this fault too basic diagnostics saw no faults and saw no air leaks but though maybe throtte body he said looks greasy and dirty near it etc. Can anyone relate i used have a mk3 and remeber topics about them and cleaning them. Does anyone know if sounds like that type prob as was going ask someone clean it, it a audi v6 2.6 by way 1997