Audi 80 tdi juddering bucking jerking

[stevegrass777]

Thanks ini for that nice pdf.
Has anyone read the bit about engine shudder suppression and the
clutch pedal switch?

[Obsidian]

Lo there all1, new member here, i'd like dto say a quick hi to all fellow Audi 80 owners.

I've had the same juddering problem as others in this thread and have yet to find a proper 'cure'. I've even experienced the dead speedo sympton and found that a good thump on the dash cured that too!

I've checked out various possible causes including the engine mounts and gearbox and clutch, all to no avail.

Thnx for the pdf file, a most informative read though i'm struggling to actually get access to the accelerator pedal actuator, which i feel is the most likely cause of the said problem. I've noticed that my engine ticks over rough, seems to be 'hunting' for a rev setting.

Earlier i was disappointed by a quick trip to Audi dealership across the road from me, who 'hazarded a guess' at the fuel pump and gave me the address for their sub-contract deisel fitter. He turned out to be less than helpful, though he said he cleaned my injectors.

Has anyone yet solved this problem? or got any idea how to get to the accelerator pedal acctuator?

[midskev]

hi wellcome to the judder club !!!

if you remove the shelf under the drivers side and the grey plastic gaurd its tucked right up on the bulkhead u need a torx key to undo the studs not a big job just back breaking i got a new one to put on so thats a job for weekend need a torx set tho lol

good luck

[hawkeye1975]

Hello, fellow judderererrreerrrrsssss

I am a new member to this rather unique club, we should all meet up then judder up the road together !!!

Anyways, any new news, symptons, well the ususal

Judder at low rpms, when i first got the car, the speedo wouldn't work for a mile or 2 then would start.

Didn't do it though until i put a tank of fuel in though.

Initially thought it was engine / gearbox mountings.

You would have thought VAG would have a solution as the engine is used in VW too, or is it an AUdi only problem, which would sugguest some electrical malfunction purtaining to Audi's only ??

Need to fix this some how, ruining a perfectly good car

COME ON AUDI, GET YOUR FINGER AUS !!!!!

[hawkeye1975]

hi wellcome to the judder club !!!

if you remove the shelf under the drivers side and the grey plastic gaurd its tucked right up on the bulkhead u need a torx key to undo the studs not a big job just back breaking i got a new one to put on so thats a job for weekend need a torx set tho lol

good luck

Let me know how you get on, if that makes any difference??

[Obsidian]

i most cerainly will, i'm assuming that midskev hasn't had any joy though, sound slike he's already had a crack at it. Look slike it might be better to take the drivers seat out to do this job though!

[Obsidian]

Lo there Midskev, where did u get your actuator/ potentionmeter from and do they come to peices at all? I think giventhat the speedo seems to affect the juddering problem then there must be something wrong in the speed control closed loop circuit, and i'm wondering if it's just a worn or poor contact slider in the potentiometer.

[ini]

Does the 'stumbling' or 'hesitation' from 1200-2000rpm go away when the engine is warm?

If it does, i would check that your 'at idle' fuel injection quantity is around 4.0-5.0mg/stroke.

Suspect fuel temp sender, or fuel pump advance mechanism.

If the problem goes away when you disconnect the speedo, the car is possibly running default values for some sensors.

[Obsidian]

the problem is there all the time m8, i mean, it never goes away or changes in intensity, it does it hot or cold. I can't say as i've noticed anyway of releiving it whilst driving, usually i drop a gear and accelerate beyond the trouble zone. and then all is ok. the car's top speed is unaffected and fuel consumption seems as normal. engine temp ok and no water loss. oh, and it ticks over rough, seems to be hunting for 900 rpm. any other clues? i'm veering away from fuel pump myself, that's a real expensive item to replace and i'm assured if it was the problem, there would be no if's or but's about it, the car wouldn't run.

[ini]

Just out of interest, does the idle rpm alter if you suddenly load the electrical system? (turn on main beam, wipers etc)

You need to post some vagcom measurements, fuel & engine temp, timing, injected quantities etc, all the normal stuff.

I am convinced that the problems are fuel pump related, the fuel pump contains quite a few devices, and the actual bit that moves the fuel very rarely fails.

It may be worth visiting a Bosch service centre and having the various pump components checked, this can be very inexpensive.

Also, do you have any means of visually checking whether there is any air entering the fuel lines?

Have the injectors been cleaned recently?