Audi 80 tdi juddering bucking jerking

[avanttdi]

ok, i give up. after weeks of trying to figure it out. has anybody else got to the bottom of the audi 80 tdi (1z engine) problem where the vehicle judders/jerks/bucks at light load at anything between 1200-2000 rpm

after this it clears, also flooring it, it will pull through.

symptoms like this have been described by so many people, but no one knows the problem as of yet.

in a few cases, it has been said that the car also idles roughly, as is the case with my car.

PLEASE HELP if you know what it might be. i will not list everything that i have done, as the list is too extensive, instead i will read comments and let you know whether i have allready tried what you suggest.

i know there are more than five people knocking around the net with this problem, and some of the posts are a year old or more, and the problem is unresolved

the closest i have come to curing the problem is unlpluggin my vss (vehicle speed sensor). this seems to eliminate the problem. however i cannot run the vehicle like this all of the time as i have no speedo or odometer and it also disables certain engine management functions.

i look forwards to hearing your replies

[baggabones]

I would guess you have checked most things but when my 80 was juddering a few years back it turned out to be gearbox to engine bolts, 3 missing and the rest loose. It was ok when I was accelerating hard but on idle and light load it was juddering quite badly.

[avanttdi]

hi baggabones. thanks very much for your reply, ill check it they are all tight

[TDi-iac]

Hi avanttdi,
As midskev mentioned on the other thread, the juddering is frequently caused by the timing belt tension (or lack of). The tensioner works on an elipsed spindle, which I am guessing wears out, causing a loss of tension.
Mine starts to judder after a couple of weeks driving, and sure enough, every time I take the cover of the front, the tensioner has slipped a little.
Try tightening it using circlip pliers (so the crescent is verticle) and see if that works. If it does, and it starts to judder again after a while, a new tensioner is certainly needed.

Of course, as other people have seen, there are dozens of other things that can cause juddering on these wonderfull cars!

[midskev]

hi hope your all well,

im getting old going grey but the old bugger still judders new cambelt and new kit pullys tentioners ect its a far more driverble and economical it dosent smoke u can even redline it unless it overboosts doesnt do that unless u floor it, pulls far better on less right foot, will i die with this problem lolol will a lump of metal plastic and rubber be the end for me, even audi havent a clue,

and does anyone know where the vaccume pipe that goes into the ecu comes from i cant see it to trace it its the only one i havent changed, going take intercooler off next and clean that out, gearbox bolts fine but i did hear thar the oil can evaperate in there so getting it up on mates ramps to check it and put some addrtive in it, and if anyones got a vaccume turbo wastgate acctuator of a 1z 1.9 tdi plss its last gasp ideas now,
i got a new throtle potentiomiter to put on i had a look need some torx spanners and lose 4 stone to get at it but ill see if that does anythin,

keep working lads then when we get it sorted we can sell the remedy to audi lolololol

ohhh ps
aint it nice to see the sun yeahhhhhhhhhhhhh

[nickysteveo1]

Hi i have the same problem at about 2000 revs.

By chance I have found that by taking out the instrumant panel fuse (no. 12 I believe) the juddering completly DISSAPPEARS. The engine runs fine.
Obviously this isn't a very good solution with no speedo and other instrument panel gauges working , but it might help give an indication of the cause.

My guess is that the on board engine computer is getting bad rev or speed information, or is malfunctioning.

Has anyone got any ideas. Could replacing the engine ECU help ?

Disconenting the rev counter?
Does anyone know how you would do that ?

please help, I can't take these shakes much more

[nickysteveo1]

Doh! sorry didn't realise you had already come across the disconecting the speedo effect.

[ini]

I would suspect fueling as the cause of the problem, vag-com readings would be a great help.

First disconnect the maf and see if it runs any better.

If not, check the injected quantities & timing are in range with vag-com etc.

Are the fuel and engine temps in range?

If you have your radio code (if needed) disconnect the battery for 30mins, and see if there is any change.

If no change, try disconnecting the engine temp sensor and see if the problem occurs.

Has the fuel filter been changed recently, + are the injectors ok?

I would suspect a worn/loose valve or advance/cam/piston mechanism in the pump.

[nickysteveo1]

thanks for the reply

There are no Vag readings,
there was a bad MAf reading a year ago and i replaced that.

Have disconected the battery and maf, but it doesn't help

Where abouts is the engine temp sensor?

[ini]

Should be located on the top coolant hose very close to the engine block.

You need to check the 'injected quantities' with vag-com.

Also accelerator pedal switch.

Could also be ECU electronic component problem though.

Here is some info relevant to your 1Z:

http://pics.tdiclub.com/data/529/135...echnik-eng.pdf