Audi 80 tdi juddering bucking jerking

[falcoron]

Hi Judders, not been on here for a while, okay, so have we finaly got a solution ?? my juddering is now accompanied by cutting out for a split second. When under load(ie going up a hill), you can feel it come off the boost just b4 cutting out. Just to add, my speedo occaisionally stops working, when this happens my Audi runs perfect, no judder or cut out.

If this wire cutting works, can some one give me the idiots guide to doing it.

Also, if cutting wires works, wouldn't it be a good idea to find out why it works ??

Thanks in advance

Peter

It works!
Lifes too short to worry why it works, just do it.
Its on here what to do and it is idiot proof. Take a look back through this thread. Its posted and i followed the instructions took me 15 mins top! car has done 6k since and runs perfect. no warning lights nothing! better MPG as well as im not reving past the judder anymore.
These cars are undoubtaly great but worthless in the real world because of there age and high miles so just do it.
I promise you will not regret It
cheers
Ron

[hawkeye1975]

Cheers Ron, Will be unbolting my steering wheel (hopefully i've got a big enough socket!!) this afternoon, as long as the missus doesn't find MORE jobs for me to do !!

Peter

[audi80nz]

Hi from New Zealand. We just bought a 1990 audi 80 20e.
It judders under load from about 60 to 80 km/h and feels like a badly balanced tyre. It goes away when you coast taking the power off.
Sometimes idles rough like its looking for fuel.
I suspected inboard C.V. until I checked this forum.
Can other judderers confirm the symptoms please.

[micheal balbrig]

Hi from New Zealand. We just bought a 1990 audi 80 20e.
It judders under load from about 60 to 80 km/h and feels like a badly balanced tyre. It goes away when you coast taking the power off.
Sometimes idles rough like its looking for fuel.
I suspected inboard C.V. until I checked this forum.
Can other judderers confirm the symptoms please.

Hello NZ Lnder

Is yours petrol model. if so there is another thread under
Audi 80 2.0L ABK Engine Juddering/Misfire
Problem with them seems to be weak soldered joints
in a relay
Diesels judder differently

[audi80nz]

Hi Michael. Thanks for the quick reply. Yes it is a petrol model. I'll switch threads to see what I can find out.

[audi80nz]

Hi. Turned out to be both inboard c.v.'s worn. All sorted now, couldn't wait for new parts from Germany so two good second hand drive shafts with c.v.'s fitted.

[shedavant]

Hi, has any1 actually replaced all sensors? mine does the hunty judder dance and when i tried to hold my revs at a steady 1500rpm to flush the engine it was'nt having any of it! either dropping or increasing!!!
Anyway, while having a few beers while giving it an oil change I slightly over filled it by a litre! tickover was spot on and it held the revs at 1500rpm no problem till i gave it a slight boot to 2200rpm at wich point I had a masive dump as the engine reved its ballbearings off due to oil in intercooler!!! after stripping all pipes and clearing excess oil its back to doing its jigg!!!
i guess its just wornout or is it???

[scotty33]

I'm not surprised it spat some oil into the intercooler with it being overfilled. I can't explain why the idle smoothed and the rpm held steady, due to the extra oil, or was it coincidence?
Have you tried disconnecting the speed sensor wire?

[shedavant]

Iv tried everything! all perishables have been replaced filters, pipes etc iv a feeling its a turbo related problem as it only seems to happen after the turbo kicks in, keeping rpm below 1800-2000rpm seems fine if your driving miss daisy! its as if its not breathing and getting clogged! could a blocked cat cause this? if the egr and inlet have gunged up does this not create cat blocking soot and the italian tune that some recomend just creates more soot, so when the turbo kicks in this just creates to much back preasure! i really havent a clue as this is my 1st audi and the only diesel engine iv ever had a problem with! might just remove cat as i cant see any sensors in on or around it! and according to my local exhaust centre cats serve no perpose on diesels anyway.

[scotty33]

I decatted my passat tdi, due to low mpg's and lack of performance. It did not improve either of these by much, but the car revved more freely at the top end and the turbo produces boost earlier. This last point might make your problem worse?
I agree the cat is not necessary for passing emissions, but it is there for a reason.
I would have thought the air pressure sensors would 'tell' the ecu if the inlet is overpressurised, the boost control valve should then operate the wastegate to slow the turbo down.
In other words, the management should be capable of looking after the boost level? If you get it scanned for fault codes it might tell you if a sensor has failed?
If the intake is gunged up, it is well worthwhile clearing this out, the difference this made for me was most welcome.
Have you read all of this thread? Most juddering problems seem to be reduced by disconnecting the vehicle speed sensor ( which is next to the CV joint on the gearbox) if this works there is a certain wire which can be cut that achieves a similar end but without losing the speedo function.
The proper cure for the juddering problem seems to be stripping down and cleaning the diesel pump which looks to be a very specialised job, involving desoldering the electrical side of the pump control.