2.0TDI 140 Hesitation and Stalling

[mscnoe]

I have an '07 Stylance which I bought as an ex demo model. Now 41,000+ miles, but has always hesitated when accelerating and occasionally stalls - usually when manouevering but once on leaving m-way - once stalled wont "bump" start - have to turn ignition back off and on again, always starts first time then. The hesitation managed eventually with Dealers help to track down to the switch on the clutch which comes into play before the clutch is actuated - apparently it brings in a torque reduction program. When moving up through the gears if my foot hovers on the peddle the acceleration is marred by short hesitations - if I deliberately lift foot away then its fine. The stalling might crop up maybe once a month, once drove for about 2000 miles with the clutch switch disabled (so no cruise control) - no hesitation and no stalling so its all linked in. Whatever is going on leaves no trace in the computer and no way it can be traced while in for a service so unless can find another way around it its there for good. Still in warranty - any suggestions?

[kenney]

Can you not just replace the clutch switch?

[mscnoe]

:biglaugh: If Only it were that simple!! I'm on my third one now - they are not designed to be removed and certainly not adjusted - sort of a sliding ratchett mechanism that sets the length as you clip it into place (whilst standing on your head trying to see what you are doing!). When you remove it internal parts lock together and by the time you have worked out how it actually works a tiny but absolutely essentail piece of plastic has pinged off into space and its good for nothing (other than discovering that with it disconnected the hesitation doesn't happen - but also the cruise control wont work and that is a licence saver!!).
Thanks for the suggestion - wonder if the fault affects this engine varaint in other VW powered vehicles - must be thousands out there!

[kenney]

The function of the switch can be checked in measured blocks.It stands to reason,if, with the switch disconnected,the engine runs ok,then there must be something wrong with the fitting of the switch-

[mscnoe]

Hi Kenney - not sure what you mean by measured blocks - it actuates before the clutch starts to disengage (tested by engaging cruise control - press down pedal gradually until cruise cancelled, still some travel before the hydraulic resistance is felt). New switch when fitted actuated pretty much exactly the same way as the old one - it sets a ratchet as it is insrted in the bracket hole and turned to lock in place.

I do have the car booked in next week so they can have another go at setting the wipers up to wipe the screen not the bonnet or the door - seems to be a load of slack in the mechanism. If there is something specific I can suggest to them to investigate it would help - all I get back is "nothing to see in the fault log". Nothing different about the warning lights when it happens - just the battery/ alternator light comes on.

Thanks again - don't know why I havent tried the forum before now!:Blush:

[kenney]

There are two types of switches one with a rectangular housing,and one with a round housing,and they have different fitting methods.Measured blocks is a diagnostic programme,in which you can see how the switch functions

[mscnoe]

I presume from this that you have had issues with these in the past? I have only seen one switch on the clutch pedal, it has a round body. The switch that is on there now was fitted by the main dealer so I would hope has been checked with the computer diagnostic - I will throw the "measured blocks" at their technical man and see if he knows what it means.

Earlier tonight I followed one of the links that the forum popped up which reffered to a Passat TDi 140 same year as mine with what sounds like a very similar problem - that ended up with his garage connecting with Germany as they have a deeper level of access to some settings and sorted it out. I wonder if Seat can do the same - something to do with fuel timing at low revs. Another one for Andy! I have noticed that the cutting out happens mostly when I have had no throttle applied before the clutch is dipped - e.g. sliding off the motorway using engne braking, dipping the clutch to drop down a gear and hearing the engine stop or descending a hill, pausing briefly at the junction then setting off only to stall mid road with oncoming traffic! - as though the emu has had the fuel cut right back, and cuts it back further to reduce torque (I thought that was what my right foot was for!) - cutting it off completely in the process.