I have a 92 Audi V8, ABH 4,2l.
Pulsating accleration, watch video.

http://smg.photobucket.com/albums/v700/ultimateVW/?action=view¤t=MOV01433.flv

ps: New Bosch Lambdasonde,plug cables- under a year old.

HI Svein,

can you please fill out the profile correctly? Location etc.

Concerning your problem:

a) What does the ECU fault memory tell you?
b) Check the ground connection of the exhaust and probably install a ground strap - still looks like the Lambda sensor doesn't operate correctly. Just unplug the sensor and test.

Bastian

i have updated profile a bit.

No fault codes now. I have changed lambda some months ago, before that i got a fault code for the lambda.
After changed, no fault codes.

Ps: before it was much engine problems.
But the wavelike acceleration is still there..

I will try to mount a ground strap near lambdasonde:-)
I have tried another lambda..

I had the same issue 2 years ago.
I have changed lamda and every thing get back to normal.
Don't use universal bosch sonde, buy dedicated.

I have exactly samelike problem, and it doesn't mutter if the rpm is 3000 or 6000 the wave is still there.
I think it is oxygen(lambda) sensor or it might be the air mass meter(or is it air volume meter).
Could anyone tell me some webstores where to find AMM's in reasonable price?(maybe order from Germany or UK or etc.) cause here in Finland the local markets give prices around 600 Euros.
Thanks

/Sam

Lambdasonde is a brand new orginal Bosch.
Tried to check it, 0,0 - 0,7 volt at 700-800rpm.
that is normal?

Also took a Compression test, 180-185psi at all 8 Cylinders.

Engine works best without the lambda connected (black-signal).
I got a tip about the 2 sensors at flywheel, what do you think?

PS: NO fault codes!

Think those two sensors aren't a problem, maybe the Hall Sensor (in your ignition distributor). Checked the grounding of your Lambda?

Bastian

i have mounted a ground strap at lambda earlier. There was no differents.
No fault codes as I say.

When i had a 86 Golf GTI 16V i changed the Hall Sensor because it did not start.

Do you know if its the same Hall Sensor in the V8 4,2 distributor?

I have just read this: http://www.audiv8.com/german/faq/faq_show.php?id=13325

As i can see this seems to be like my problem.
I have ordered a brand new distributor, 80GBP + shipping.

Hej Svein,

you would have been able to exchange the sensor without exchanging the whole distributor. Well, too late I guess (and easier that way).

Regards

Bastian

Yes i know that:-)
But the price difference was not big, and its brand new complete.

I have readed at some forum that the engine will change the ignition (6-7 degrees) if the G40 sensor is defective. And it will be slower,less responsive etc.

looking forward to see;)

Hej,

looking forward to your report!

Bastian

Just got a new distributor, but its wrong
This one is for a 5 cylinder engine.

So i have ordered a Pick up sensor that is Vehicle Compatibility with V8.

PPU2744- BOSCH 1237031339

Hi,

what are you going to do with the wrong distributor? Send it back? Why not taking the one from the V8 from Audi?

Regards

Bastian

im selling the wrong distributor.
I ordered a Distributor that was Vehicle Compatibility with Audi V8, but it was not..

So i just waiting for a pick up sensor/camshaft position.
Have changed one before in a distributor that look like the one in V8.
The hardest part is knocking out the splint

Hope it will be here in 3-4 days...

and when the gasket (Material like Bakelit) breaks you dont win the Game

Gasket with bakelit??
Where is it?

on the Weel of the Distributor... show @ Attachment, the broken part i mean

Hi,

Any progress? Did you found new hall sensor and/or whole distributor?

I measured my air mass meter and it's faulty, gives only 3.3 volts on 4000rpm and now needing new one.
Does anyone have ideas where to find one in reasonable price?

Regs Sami

Hi Sami,

best is to head for the market place here in the Forum (left menu) and ask for one! They brake pretty seldom, hence it makes sense to take a used one for little money.

Bastian

I have changed the Hall-giver. No difference..
What next?
ECU damaged?
The 2 sensors at flywheel?

Im getting sick of this problem.

Hey man! U live in Norway right? I live in Eidsvoll. And I got VAG-COM that may set us on the right track.

I bought a sparepart/donor V8 for my V8 project a fiew years ago. It had the same problem. And I`m planning to use that particular engine for my car when I`m done. So for that reason allso, It would be interesting to try to help you...
(Guess cars aren`t moderne anymore when I`m finished...)

Have you checked the signal? I belive you wrote that it was 0,0-0,7 volts. the important indication is wether or not the signal oscilates (goes up and down). If it does not - (After the engine is worm) the lambda is screwed!

Looking forward to hear from you!
Per-Stian

Forklar gjerne på norsk:-)
Du er medlem på VACN klubben, sett deg der inne.

Jeg har jo prøvd å byttet lambda 2 ganger. NYE!
Ingen forskjell. Jævlig rart.

Hejsa

Har du også prøvet at lægge en extra stel ledning til lampda'en
det kan godt være et problem med stel

Hilsen fra DK

jepp..
Ny lambdasonde (prøvd 2 stk)
Ny hallgiver i fordeler
Pluggledninger, plugger som nytt
Montert jordingskabel mellom lambdasonde og motorblokk.
Kompresjons test- 180-185PSI på alle sylindre.

Av og på følelse under akselerasjon. Fin ved fullgass.
Kobler man fra lambda blir den fin.
Typisk kjennetegn på at lambdasonde er defekt- men ikke hos meg..
Kan Hjerne/ECU være ett forslag å bytte?
De 2 sensorne ved svinghjul?

Det sto forresten en Biltema universal lambda på bilen når jeg kjøpte bilen. Under en Måned senere begynte den å fjuske mye, sjekket feilkoder. Lambda kom opp.
Skiftet den og fjuskingen forsvant- ingen feilkoder etterpå. Men den hadde/Har pulserende- Av og på akselerasjon.
Feilkodene ble selfølgelig slettet.

Benny
Om du ser over i tråden ser du at han har prøvd det, men tipset er absolutt ett bra tips..

(Danish friend suggesting a separate grounding wire - But this has allready been attempted without further luck....)

Svein:
Som jeg skreiv så er den første indikasjonen på at lambdaen lever at signalet (volten) du leser av på den svarte ledningen flukturerer. vanlige verdier jeg har vært borti på S6 4,2 AEC og 100 2,8 Q (denne har to) er at signalet skal flukturere/ "svinge" rundt 0,6 volt. (Mål imellom jord på karrosseriet og den svarte signalledningen) dvs opp til ca 0,8-0,9 og så ned til 0,3-0,4 volt. Jo varmere den blir, jo fortere svinger signalet. Dersom den gjør det kan du "friskemelde" lambdaen. Det er viktig i feilsøkingen at du får "røyka ut" om dritten funker eller ikke. Det er ikke "bankers" at deler du kjøper funker 100% . Dersom den gir det signalet jeg beskriver kan du fortsette.
Har du forresten lest ut feilminnet på bilen noen gang?

In English:
As I wrote: the first indication of life from the Lambda is that the Signal (Voltage) You can read from the black wire is fluctuating/Oscilating. Values I`ve been aquainted with on S6 AEC and 100 2,8 (This actually has two sensors) is that the signal should Oscillate around 0,6 volt. (Measure between ground on the chassis and the black signalwiere) In other words: signal should reach 0,8-09 volts and then return to 0,3-0,4 volts. The warmer it gets, the quicker it oscilates. If it does - the Lambda is fat and happy, and you should proceed... don`t settle just because you have replaced it. Measure and find out for real that it works or not. throwing parts at it is just expensive.
Have you ever attempted to download the fault memory?

Best regards from Eidsvoll Norway
psb

Har lest av feilminnet ja. Det gjorde jeg når Biltema universal Lambdan begynte å tulle. Les forrige innlegg.
Begge de 2 Lambda jeg har prøvd er splitter nye Bosch.

Another issue is that the above mentioned test is just an INDICATION. the values might actually be faulty, but because the value oscolates and stay between the mentioned above 0,1 volt and under 1,2 volt the ECU will not understand that the value is wrong...this sucks - but is just the way the system is designed.
I know some engines are really picky about wich Lambda they get. Is the one you tried an Original from VAG?

I belive the two sensors on the fly wheel (Engine speed and TDC) are either working or not. Nothing in between. If the dont work, You sholud get a fault code.
psb

Orginal from VAG yes...
It run ok with a BILTEMA universal Lambda when i bought the car....
Har du ei Hovedlykt til overs? venstre side foran.

OK so the Lambda should be OK. But still do the test, and see if it oscilates. If this does not work, and as you say the engine runs smoother without the lambda (In limp home mode) this indicates that there still is "gremlins" in the exhaust "follow up/feedback system".

The next Idea i have is to ask one of the suppliers that sell chip upgrades. Some of these guys really know what they are talking about. And he would definetly be able to tell wether the lambda function is working or not if he hooks the car up to hes computers. Tell me if you do, bacause I would really like to show up and learn - If you don`t live to far away.

Best reards from Eidsvoll.

Another thing you can check, that I found in my workshop manual is the initial signal from the ECU to the Lambda:
LAMBDA HEATING:
For Lambda heating I was not able to find a Voltage, the manual just directed me towards hooking up a Diode flash tester and a procedure I`m not familiar with. The PT ECU calls for a Voltage of 12-14 volts when you disconnect the heating wiering, and check between terminal 1 and 2 (white wieres) on the hareness to the ECU. Maybe these values are valid for the ABH as well?
CAUTION: YOU NEED TO KNOW WHAT YOU ARE DOING TO CHECK THE FOLLOWING. IF YOU GET IT WRONG YOU MAY TOAST THE ECU!
If you hook up the Multimeter in series and look for the current, it should be between 0,5 and 3 Amps.
LAMBDA SIGNAL:
The only data I was able to find was a voltage signal of 450mv (+-50) between Engine ground, and the Signal (black) wiere from the ECU. (Lambda disconnected) I was not able to find any "live" signal for the ECU in the workshop manual...

good luck!
NORWEGIAN
En annen ting du kan sjekke, som jeg fant i verkstedshandboka mi, er utgangssignalet fra styreenheten til Lambdaen: LAMBDA FORVARMING: ang. forvarming fant jeg ikke noen spenning, boka bare ledet meg til en prosedyre med diode blinkelampe som jeg ikke er kjent med. det eneste dette ville indikere er at utgangsspenningen når du kjører denne testen er høyere enn 0,6 volt. For PT motoren (3,6) fant jeg en spenning på 12-14 volt imellom terminal 1 og 2 (de to hvite ledningene) når motoren går, og du sjekker ledningene som kommer fra ECU`en. kanskje disse tallene funker på ABH`en også? en annen og sikrere test er viss du kobler inn ampermeteret for å måle strømmen som går med til forvarmingen. HER MÅ DU HA TUNGA RETT I MUNN. VISS DU KOBLER FEIL KAN DU TROLIG TOASTE STYREENHETEN!
LAMBDA SIGNAL LEDNING:
For selve signal ledningen skal ECU`en legge ut en spenning på 450millivolt (+-50). Jeg kunne desverre ikke finne noen "live" verdier for måling på lambdaen når den er koblet opp mot motoren og skal gjøre jobben sin. men prinsippet med osilering skal gjelde også her.

lykke til!

psb

Im having the same problem, but my car also dies randomly. Anyways, I unplugged the cam position sensor (hall sensor), and the problem went away. Are you sure you replaced the sensor right? Making sure it was timed right?

there are two different lambda sensors on the v8 quattro that will cause this. One is the oxygen sensor located in the exhaust, and the other is a coolant sensor on the back of the right head. Both of these must be working correctly to prevent the "hunting idle " you are experiencing. Allan

i see that one of the Distributor cap does not look right.
The middle part for the coil plug- little metal thing inside with a spring.
Its sitting to far inside!. That its not right.
i
Im looking foward to see if my problem will go away after changing that distributor cap.
Will see next week..
i

Please tell us when the problem is solved.

No difference changing the distributor cap. Also changed the temperature sensor behind one cylinder head.
Is there anyway to check the TPS sensor?
ohm?

TPS?

This is a English part of this forum. Please write english.

This is my signature, man! IF anybody in here is trying to support the non-German people in as well, it may be me...

So what the heck does the acronym mean?

Throttle Position Sensor.

Thanks

Regarding the initial problem: The air mass flow sensor is OK?

Bastian