tdi hesitation

[mikeya4]

hi i have a a4 tdi 90 engine code ahu. every now and then it starts to shudder, it only does it between 1200-1500 and normally under light load, if i put my foot down its fine, i've had a new maf and theres no fault codes, any ideas?
thanks
mike

[graememwagg]

Hi Mike,

I have a 2000W 1.9TDI 115 SE A4 with exactly the same problem. I’ve just joined the forum to hopefully find a solution!. I took the car to a local VAG specialist and they tried a few things over the course of a day and a half. Service history is perfect, always used VAG parts and oil etc. New MAF fitted last year too. The garage checked, compression, fuel lines, filters swapped out MAF etc etc. But still no joy! I’m able to make the car do it on demand (well coming off roundabouts anyway). I’m going to take one of the engineers out to show them the problem as they seemed to have difficulty in getting the shudder/judder to happen. Mine seems to start judder at about 950rpm through to 1500, very light throttle regardless of gear.

I’m sorry I can’t help you here, but it’s nice to know I’m not the only one! I’ll keep you posted with any findings (won’t be for a couple of weeks though). Please let me know if you get any joy in resolving the issue.

Cheers Graeme

[mikeya4]

i've managed to find my problem, it was a vacuum hose that goes onto the airfiler box, it wasn't even attatched, I pushed it back on and its been fine since, hope you find out yours mate

[graememwagg]

Interesting... I’ll take a look, this problem is doing my head in.

Many thanks.

[justin@justinwa]

ive got the same problem with my a4 115 tdi 2000 w read how far we have gone to get rid of this problem fly wheel, injectors,filters maf,loads of money spent ive posted many times about it with no real response

[adele562]

hay im new to this aswell, and from what i see we are all having similar problems only i have by passed all the problems you are having and i am now at the car cutting out when you rev it over 3 rpm and taking two three attempts to start! i also have a 1.9tdi 90 ahu on a 99plate! audi seem to have never heard of the problem, its frustrating me not having the car and whats even worse is i come on this and find many with tha same problem!!! :zx11:

i have had the diesel pump re-cond, glow plugs, timming belt, new cam pully, then new piston two new valves head skimmed and it dropped a valve again so i got a new engine which was checked in the old car before swap and ran fine but still wouldnt rev past 3rpm in my car! i also had the ecu sent away to be re-cond and still no difference :zx11::zx11: i have only had the car since november and i am throwing money at it now!!! (which i dont have) today the accelerator pedal is being changed as it is fly by wire and the box is on the side of the pedal so i will post if i have any joy

sorry for the rant! :aargh4:

[justin@justinwa]

please let us no how you get on. i have blanket off the egr valve today took off the inlet manifold cleaned it new filter checked all the loom in the head again!checked every pipe i can see this car is driving me insane i hate this car! This car is fine and revs fine until you drive it!

[adele562]

hay, well no joy it didnt make the slightest bit of difference!!!! :zx11: its booked into a diesel specialist on monday who has just had an audi b5 in for the past four months, so hopefully he knows the problem as he certainly wont be having my car that long!!!!! again if i have any success i will let you all know!
i think we should all join forces and approch audi with the problems we are having! (with guns lol) not :D

[micheal balbrig]

Hello

Audi 80 TDI 1994 model suffers same problems

More info @

Audi 80 TDI Juddering Bucking Jerking

Audi 80 TDI Estate -are they any good

Juddering or Missfire

Audi 80 TDI Juddering Problem

Audi 80 TDI Bucking Jerking

[Audidothat]

Hi Mike,

I have a 2000W 1.9TDI 115 SE A4 with exactly the same problem. I’ve just joined the forum to hopefully find a solution!. I took the car to a local VAG specialist and they tried a few things over the course of a day and a half. Service history is perfect, always used VAG parts and oil etc. New MAF fitted last year too. The garage checked, compression, fuel lines, filters swapped out MAF etc etc. But still no joy! I’m able to make the car do it on demand (well coming off roundabouts anyway). I’m going to take one of the engineers out to show them the problem as they seemed to have difficulty in getting the shudder/judder to happen. Mine seems to start judder at about 950rpm through to 1500, very light throttle regardless of gear.

I’m sorry I can’t help you here, but it’s nice to know I’m not the only one! I’ll keep you posted with any findings (won’t be for a couple of weeks though). Please let me know if you get any joy in resolving the issue.

Cheers Graeme

Hi Graeme

Got the same car with the same problem, although mine at the moment is intermittent. Just wondering how you got on... Mines going in Wednesday, would be nice to know what to expect..

Regards


Martin

[justin@justinwa]

before you go any further with this car get the fuel pressure tested at the tandem pump you need 3.5 psi at least

[graememwagg]

Hi everyone,

I hadn’t seen any email notifications about this activity on this thread and just found my own post (here) via Google! The plot seems to thicken…

I had a K&N air filter fitted and checked that is was seated correctly a couple of weekends ago. This temporarily solved the problem, but soon enough (less than 500 miles later) the hesitation is back.

I’ve read somewhere that if too much oil is used in servicing the “lifetime” K&N filter that it can cause problems with running. So I’ve removed the K&N filter and replaced it with the Audi one I took out originally. The problem seems to have subsided significantly.

Still not happy its fixed thought. Has anyone had any other ideas?

ALSO:
I noticed a foam/sponge type material on the inner of the tubular pipe (Inlet to engine for air filter box), should this be there? If so should it be really clean? [Excuse the amateur terminology, I’m a sparky chap not a mech man]!

Thanks,
Graeme

[vbadlak]

Hiya Guys, I am also having exactly the same problem, only started 2 days ago judders about 1700 rpm, I have been advised that it is either the mass fly wheel or the ECU either way both about 7-800 to get sorted. I hope someone can come with a cheaper cure soon as it is not that bad as it only happens during these revs.

any joy from anyone its also drivin me nuts as i just bought the car

[Audidothat]

Hiya Guys, I am also having exactly the same problem, only started 2 days ago judders about 1700 rpm, I have been advised that it is either the mass fly wheel or the ECU either way both about 7-800 to get sorted. I hope someone can come with a cheaper cure soon as it is not that bad as it only happens during these revs.

any joy from anyone its also drivin me nuts as i just bought the car


Hi, been meaning to get back to this, had mine checked, and initially no faults found, it was only when they replaced the MAF with a spare that the fault was found. So in short, they replaced the MAF with a new unit, and everything is now good!:biglaugh:

[vbadlak]

Hey that was lucky lol, but unfortunately my MAF has just been changed a week ago, and still no joy, if anyone has any other ideas please could you let me know.

[mikeya4]

mines sorted now, even though i had a new maf, i thought id try giving it a clean and changing my air filter and its perfect now, never using a k+n again!

[vbadlak]

I am still not having no joy, given it back to the workshop to see if they can find a cure, they said they will replace the MAF again with a spare, we will see what happens hey.

[graememwagg]

Finally got to the bottom of the problem… one word TURBO!
My turbo blew up, turned out that the pressure release mechanism was sticky and the turbo was running on overpressure/overboost. So after lifting off of the throttle and then applying throttle again (lightly) the pressure in the turbo was incorrect. Apparently sometimes the ECU puts the engine into limp mode – not in my case.
Got a fully warranted refurbished unit from Turbo Technics www.turbotechnics.com (http://www.turbotechnics.com/) in Northampton (highly recommended), £423 inc VAT, trade of my duff one and a gasket kit, a late evening of fitting – and now running better than ever!
:biglaugh:

[vbadlak]

Hiya, thanks for letting me know, unfortunately cant get it done at the moment due to lack of funds, but will change it soon.

regards

Vee.