Audi 80 tdi - juddering problem

[Jonathan84]

I have had a similar issue with our 1992 tdi from 1950-2150 revs. It is a slight judder under full acceleration, though nothing more. I generally just try to keep the revs higher when accelerating, though it is annoying to a degree as it makes cruising at 55-60mph in 5th a pain if my speed isn't constant.

[krissib]

dont know if any1 is still reading this thread, ive got a 1993 audi 80 1.9 tdi, its about 165k now was 100k when i got it, its juddered since soon after i got it, the person i bought it off swears it never did it b4 but it had stood still for 6 years or so....

anyway just wondered if it helps any of you, but my car is an automatic and still judders...

recently (in the last month) its started dying at certain speeds... feels like the turbo kicks in and out... which is even more annoying than the jerking.... although the jerking seems to have stopped as much, it now feels like im losing half the power every time i hit a slight hill....

is it too late to cut the wire?? i was hoping whatever it was that needed replacing would also stop the jerking, but after reading all these pages im now more confused than before!

my fuel gauge does weird things, it lies to you about how much is in it if its under halfway, can drop to nothing or hover in between the reading or empty... ive read loads of posts that say fuel pump which is plausible but one post did say about dry joints in the dash.... does this tie in with the blue/white wire theory?

im fairly sure i get air bubbles in the fuel line as well, god knows where from, ive replaced the fuel line (cos it failed the last mot on it)

i seem to find new filters (air/oil/fuel) seem to stop the juddering for about a week then it kicks in again....

i modded the woven waste pipe as well soon after i got it, replacing with a solid plastic tube.... that seemed to help for a bit but i dunno whether to just ebay it and try and find another car or whether to venture further....

i was hoping after 20 pages there'd be a reason that all this happens... some people say about a turbo pipe... sounds like mine is starting to go, or could it be the computer thing idling me out because of the fuel gauge etc....

im more confused now than ever lol and i need a reliable car!

[allan_audi]

It seems to me the reason for the juddering is the Diesel Fuel pump. Its just about the only thing I haven't looked at. A couple of people have confirmed on the forums that this has stopped their judder.

Trouble is the pump is expensive, even a recon unit will cost £400. I've been happy with the vss wire cut modification. The car drives near perfect. I don't see the point in repairing the pump unless I can get a cheaper one.

I've seen articles on the web explaining pump overhaul (in German) and the presence of metal fragments in the internals which cause problems. But, the pump is fairly complicated and so I can see why the recon units are so expensive.

So, unless you want to fork out £400 I'd just cut the VSS wire and enjoy the car............

[allan_audi]

krissib,

Sounds like you have a combination of problems here!!

The lack of boost sounds like either your boost pipe is loose or split. The top boost pipe into the manifold has a habit of splitting, mine had come loose so the boost pressure was escaping. Basically check all your boost pipes from the turbo are ok.

The 80 does suffer from dash problems, my temp gauge was only showing partial temperature. I checked everything, the sender, wiring etc. In the end I tweaked the adjustment pot, a little screw behind the gauge by a small amount until the gauge was reading ok, although your problem sounds different. I have heard that the voltage regulator on the dashes can play up too. This might be the problem with your gauge. Its a small three legged device on the back of the dash. From what I remember one pin is ground (0V), the other battery (+12-14V), and the other 10V regulated. Check the voltages are ok in particular the 10V. You can get an equivalent part, its on one of the forums.

Sounds like the judder is diesel pump related and I'm sure that one of the signs is air in the fuel lines. I ruled out any leaks because I replaced all fuel lines and filter housing only to still see bubbles.

Hope this helps,

I've been driving the Audi for a year or so with the VSS wire cut and it drives fine.

dont know if any1 is still reading this thread, ive got a 1993 audi 80 1.9 tdi, its about 165k now was 100k when i got it, its juddered since soon after i got it, the person i bought it off swears it never did it b4 but it had stood still for 6 years or so....

anyway just wondered if it helps any of you, but my car is an automatic and still judders...

recently (in the last month) its started dying at certain speeds... feels like the turbo kicks in and out... which is even more annoying than the jerking.... although the jerking seems to have stopped as much, it now feels like im losing half the power every time i hit a slight hill....

is it too late to cut the wire?? i was hoping whatever it was that needed replacing would also stop the jerking, but after reading all these pages im now more confused than before!

my fuel gauge does weird things, it lies to you about how much is in it if its under halfway, can drop to nothing or hover in between the reading or empty... ive read loads of posts that say fuel pump which is plausible but one post did say about dry joints in the dash.... does this tie in with the blue/white wire theory?

im fairly sure i get air bubbles in the fuel line as well, god knows where from, ive replaced the fuel line (cos it failed the last mot on it)

i seem to find new filters (air/oil/fuel) seem to stop the juddering for about a week then it kicks in again....

i modded the woven waste pipe as well soon after i got it, replacing with a solid plastic tube.... that seemed to help for a bit but i dunno whether to just ebay it and try and find another car or whether to venture further....

i was hoping after 20 pages there'd be a reason that all this happens... some people say about a turbo pipe... sounds like mine is starting to go, or could it be the computer thing idling me out because of the fuel gauge etc....

im more confused now than ever lol and i need a reliable car!

[krissib]

so your advice is just cut the wire and check the turbo...?

as i said before, its an auto gearbox, has the wire def been cut and worked with the automatic model??

thanks for your replies, i was hoping id hear from you, you've been one of the main people on this thread....

im not bothered about dash gauges being wrong as long as it doesnt affect the ecu! the only reason i asked was because someone had earlier said that the fuel gauge being wrong may be either the cause or the result of the ecu reporting bad information and idling the car out to protect the engine (again ive read this in many places...)

to be fair its juddered for 70k, started off doing it in damp/rainy conditions (although ppl on here swear damp is better!)

my theory until i started looking into it since the turbo dying was that either the turbo or something wasnt releasing to the exhaust until u floored it, a bit like an engine brake in a truck can block the exhaust....

anyway like i say as long as im safe in an automatic (hillstarts with no clutch etc...) ill def be snipping the blue/white wire and ill have a look for dry joints....

thanks

krissi

[scotty33]

Krissi

This thread might be some help with the gauges?:

https://www.vwaudiforum.co.uk/forum/s...ead.php?t=8426

[krissib]

hmmm dunno

had a read of it, its just the fuel gauge with the fault, temp is ok... dont think its dry joints either cos mine shows accurate over 50% full, then goes mental after that, id say that all of my problems point to the fuel pump/tank filings/air bubbles/and gauge float (assuming there is one..)

juddering etc seems to have stopped while the turbo is being weird just to update... seems to be going up hill that the turbo is dropping out... its either a judder OR no turbo unlike other ppl report, most ppl have said the turbo dies b4 the juddering starts..... will look under the bonnet this week for obvious looking things, im not a mechanic by any means tho

krissi

[helmsy157]

hmmm dunno

had a read of it, its just the fuel gauge with the fault, temp is ok... dont think its dry joints either cos mine shows accurate over 50% full, then goes mental after that, id say that all of my problems point to the fuel pump/tank filings/air bubbles/and gauge float (assuming there is one..)

juddering etc seems to have stopped while the turbo is being weird just to update... seems to be going up hill that the turbo is dropping out... its either a judder OR no turbo unlike other ppl report, most ppl have said the turbo dies b4 the juddering starts..... will look under the bonnet this week for obvious looking things, im not a mechanic by any means tho

krissi

Hi all I have four of the 80 tdi and all have had this fault, and in every case after checking for any leaking pipes, the judder from 1200 to 2000 and then gone has always been solved by cleaning out the filings in the injector pump.There is a good thread with pics on how to do this and I will always help via this site if needed

[helmsy157]

Hi all I have four of the 80 tdi and all have had this fault, and in every case after checking for any leaking pipes, the judder from 1200 to 2000 and then gone has always been solved by cleaning out the filings in the injector pump.There is a good thread with pics on how to do this and I will always help via this site if needed

PS I have a stock of the seal kits for this if needed

[frielp]

Swarf in the top of the fuel pump is the problem.