Recently bought a 1.9 TDI with 140k and 14 skoda stamps so well looked after, but noticed yesterday on the motorway that if I floor it in fifth it feels like its misfiring,

Revs don't shoot up so its not clutch slipping and it does accelerate still.

Doesn't really seem to do it in other gears.

What year is the car? If it's a late 55 onwards Google 'Fabia BLT stutter'. 

 

I'd also suggest maybe running something like this through a tank of fuel to see if it clears it up. 

 

If you have a laptop you can also download VCDS lite and buy a cheap interface cable from e-bay for the ability to code read the ECU and log a number of things to help pinpoint the issue if it still persists. 

Your putting the biggest load on engine in fifth,would probably do it in fourth and third if you find a steep hill and load the engine up.

Any other noises?

Is it remapped?

Its a 51 plate. Completely standard

Nothing else that I've noticed.

Edited 30 August, 201510 yr by dozzum

when did it last have a new fuel filter

Not sure but its been serviced every year by Skoda so I doubt its that, will probably change it anyway.

I've got a full version of VCDS.

No fault codes when I last scanned it, won't be able to play with the car till next weekend.

What would you suggest I log and what am.I looking for?

Cheers

Ok.

Changed the fuel filter today and cleaned out the egr to make sure its shutting properly.

Egr didn't look very mucky.

All the readings on VCDS were within limits at idle and also the 3000rpm 3rd gear full load ones.

Took it on the motorway and couldn't get it do do it anymore except once at 100mph.

So hopefully whatever it is is clearing itself out.

It's gonna get a few tanks of Shell nitro diesel to hopefully clear anything out that was causing the problem.

Maybe the injector loom breaking down or the start of injector failure perhaps. no excessive smoke when it does it or anything?

No smoke whasoever.

I don't think its an injector breaking down otherwise the injection quantity deviation would have shown it up.

There was an intermittent code for an implausible signal on one of the injectors, but it didn't come back at all.

Is the injector loom a common fault then?

Is it easy and cheap to replace?

I'll keep scanning it to see if that code keeps appearing, strange it only does it at high speed in fifth though,.you'd think engine vibrations at high revs in other gears would do it aswell.

was it quiet on the autobahn???   

Loom fault is quite common.