Still juddering!!

[Godzilla]

My 16v is still juddering when running at normal speeds. She has now had.... new distibuter, dizzy cap, rotor arm, HT leads, plugs, all breather pipes cleaned out, battery and a tune up at my local garage and still the juddering lives  Its not a major judder, just kind of a slight misfire feeling. Once i floor her she is fine, picks up well all the way to just under 7000rpm....its just at lower speeds. Im in huge need of advice here VW friends to what it could be! Two more things i have thought of are...fuel filter has not been changed & she came with this Pipercross induction filter. It does not sit in the original airbox, its kind of by itself with the top part of the airbox on top....which is loose by the way, could either of these cause the judder??
Any help/advice would be great!

[Gambit]

i would suggest trying an original airbox

[Ryan]

Hi Paul i think i have the same thing airbox as you. Is it just a complete foam filter with the metering head attached to the top? I had a similiar problem and all i done was cleaned and degreased all the filter and metering head and all the way up to and including the throttle body as they were extremely clogged up and it cured the problem. I am not saying this is what is wrong with yours but it did help mine.

ryan

[homer]

it must be in the air im getting same problem wit my 16 driver and i have tried every thing the only thing i need to do is timing but got to find cheapest place to have it done

[jezza16v]

Sounds like you have one cylinder not working as well as the others at lower rpm , check for......
Air leak into one cylinder via inlet manifold gaskets....
Air leak into one cylinder around injector, (they are just a push fit with a couple of O ring seals)......
Possibly one injector not working properly at lower flow levels.....
Possible leak in brake servo vac pipe, this feeds into inlet manifold at #4 end and would affect that cylinder more than the others..
Lower compression on one cylinder due to valve leakage or ring wear...I hope not. . suggest compression test.......
All the above will be less noticeable the higher the engine revs.
Unlikely to be an ignition problem as you've replaced everything.....
Unlikely to be air filter as would affect all cylinders equally....
Let us know what you find.... 

[Godzilla]

Thanks for the advice Jezza!! Be ready for a call as me and mechanics dont see eye to eye so i may be calling for your help 
Im going to get shot of the air filter....dont like it!

[Agreeable Slick]

more than likely just a split vacuum hose on the engine. Just have a look around and replace any old dodgy looking ones.