Audi 80 tdi juddering bucking jerking

[falcoron]

have you tried the white and blue wire behind clocks its a ten minuete job worked wonders on mine every little helps to keep these great motors going.

Good greif!
People ask for help, you give them a solution that costs zero and take mins to do and they still want more? cant understand it
When i first got this i went onto this forum found the link and read everyone until someone actually found a cure or fix. Easy! found one that works and cost frig all. What more do you want?

[mangojuice]

Hello Spilleddwarf

My diagnostics recorded the following items:

Address 01: Engine Labels: 028-906-021-AHU.lbl

Address 03: ABS Brakes Labels:4A0-907-379.lbl

Address 15: Airbags Labels: 8A0-959-655.lbl

Address 25: Immobiliser Labels: None

I'm told that due to the age of the car, that's all it'll pick up. Not much help I'm afraid. This was done on a windows based VAG/VAS emulator. VCDS version release 805.0. Data version 20080616. I wish I could be of more help but your symptoms appear different to mine. Best of luck anyway.

[hawkeye1975]

cutting the wire behind the dash eliminates the judder, but the power loss and (on mine anyway) cutting out still carry on, i think this is caused by the No3 injector (the one with the wire).

[iancrawford]

Hi fellow judderers, I've recently bought an Audi 80 Avant 1.9TDi 1z engine and yes it displayed exactly the symptoms described throughout this thread. Driving the car had become a nightmare trying to drive through the juddering/jerking at low revs sometimes to the point of being dangerous when trying to exit corners, the power unit leaping around unless the accelerator was almost pressed to the floor to power out of the judder zone.
Disconnected the VSS cable from the gearbox initially to see if that helped, obviously the speedometer stopped working but the symptoms disappeared.
Followed the advice of cutting white/blue wire (cut this at the ECU end to save removing dashboard), the car now runs smoothly with the added advantage of improved mpg. No warning lights, no side affects, and best of all, no judder.
Thanks for the help guys.

[allan_audi]

cutting the wire behind the dash eliminates the judder, but the power loss and (on mine anyway) cutting out still carry on, i think this is caused by the No3 injector (the one with the wire).

Hi, Its interesting because I have the intermittant cutting out and I know that its the 3rd injector. I've removed it several times and cleaned in an ultrasonic bath. It works ok for couple of weeks then starts to play up again. So I guess it needs a new one, its on the verge of bein really annoyin cause when you want to have some go it starts to play up. It usually clears within a couple minutes then drives perfect for several journeys.

The power loss I had sorted when I first bought the car. The boost pipe had come loose. Check that you're not losing boost anywhere, maybe fit a boost gauge temporarily to check. Are you saying that you get power loss seperate to the cutting out??

In the next couple of months I'll be fitting another diesel pump from a friend of mine. So finally I'll be able to prove if my suspicions are correct, that its the pump causing the original juddering. I'll reconnect the VSS signal and check.

Al.

[hawkeye1975]

Hi Al, i get loss of boost normally just before the cutting out, then you know she back to normal again and not gona cut out cause the boost comes back!!

I have tried an experiment, you try, see if your cutting out occures when you wiggle the steering while driving, basically causing lateral force, like when you go round a bend at speed

[micheal balbrig]

Hi, Its interesting because I have the intermittant cutting out and I know that its the 3rd injector. I've removed it several times and cleaned in an ultrasonic bath. It works ok for couple of weeks then starts to play up again. So I guess it needs a new one, its on the verge of bein really annoyin cause when you want to have some go it starts to play up. It usually clears within a couple minutes then drives perfect for several journeys.

The power loss I had sorted when I first bought the car. The boost pipe had come loose. Check that you're not losing boost anywhere, maybe fit a boost gauge temporarily to check. Are you saying that you get power loss seperate to the cutting out??

In the next couple of months I'll be fitting another diesel pump from a friend of mine. So finally I'll be able to prove if my suspicions are correct, that its the pump causing the original juddering. I'll reconnect the VSS signal and check.

Al.

Just something I discovered in case it may be of help.
The 93 model differs from the 94 one
I.E. The electronic actuater unit from the 93 Injector
pump would not allow engine to rev up on the 94 model it would only tick over
therefore it may be necessary to have identical models for swop

[avanttdi]

Wow! Hello again guys. I am the original creator of the thread way back in June last year, i haven't been on here for ages but it seems we have a few new members to our club. And the thread is HUGE. Last time i checked it had 14 pages.

It also seems that we have helped a few people to 'bypass' their problem with the VSS mod.

I have found a permanent solution to the problem, in the form of a 2000 A4 tdi. The 80 was sadly sold but is still going strong ( I pass her most days )

Anyway, good luck to you all if you ever do find the cause of this annoying problem.

Avanttdi

[iancrawford]

Hi fellow judderers, I've recently bought an Audi 80 Avant 1.9TDi 1z engine and yes it displayed exactly the symptoms described throughout this thread. Driving the car had become a nightmare trying to drive through the juddering/jerking at low revs sometimes to the point of being dangerous when trying to exit corners, the power unit leaping around unless the accelerator was almost pressed to the floor to power out of the judder zone.
Disconnected the VSS cable from the gearbox initially to see if that helped, obviously the speedometer stopped working but the symptoms disappeared.
Followed the advice of cutting white/blue wire (cut this at the ECU end to save removing dashboard), the car now runs smoothly with the added advantage of improved mpg. No warning lights, no side affects, and best of all, no judder.
Thanks for the help guys.

Just an update on the above,
After cutting the vss cable the car did indeed drive a whole lot better but it still had the annoying habit of 'hunting' at idle with a strong smell of fumes and was difficult to drive over bumpy roads sometimes needing to push the clutch in to stop lurching at low speeds.
I was lucky enough to locate an injection pump from a 1996 Passat 1z engine, the only difference I can see is a different loom connector which is easily modified. After fitting the pump and reconnecting the vss lead, the car runs absolutely perfectly, super smooth with no lurching, bucking or jerking. Result!
I have spent quite a lot of money renewing suspension bushes, brake discs, fuel pipes etc so I was determined to get the car running right to get full benefit.
The fault on my car at least was obviously the injection pump and now I can enjoy the driving the car as Audi intended.
Hope this helps.

[330demon]

Hi - probably too late to help you out with this one but anyway...
I had exactly the same problem with a 110bhp Passat TDI last year - problem only occured up to 2000 rpm then dissapeared. After much research I discovered it was due to the "needle lift sensor" in the injector on cylinder no.3 which was sticking and causing lack of feedback to the engine management relating to fuel injection timing. The car would buck and jerk really violently at times - solved the problem by replacing all 4 injectors with brand new OEM - diy job tool approx 2 hrs, the ones I removed were badly clogged upon inspection (approx 120,000miles on them). Car instantly fixed - have driven a further 10,000 miles since with no probs whatsoever and running/idling smoothly with noticeable power increase. I think you may have the same problem. The injectors in question were Bosch and were just standard non-PD type. Hope this helps!!