forum.audiv8.com Foren English Audi V8 Forum V8 4.2 :Start ,and stalls after a few minutes ?

Hello Guys (and girls)

I did buy a 92 V8 4.2 with 170 000 km in Schweitz
The car is in very good state of repair ( CEO of a big company)
BUT i did take it back to my country ( Frankreich) with my trailor:
In fact the car starts , it run for about 5 minutes and then stalls

The only fault code number is (with but the engine not running) 2111 or 2112 (RPM and TDC sensors) fault code or 2234 (supply Voltage) fault code. But SJM wrote that it is possible to get those "false" fault codes.
I have a 200TQ20V Avant and this errors codes dont mean anything.

My question is : Is my problem a problem that occurs often with V8,( I thought sensors don't really get old, there is no contact ,it is rust free , just some l vibration , like abs sensors)

and do you think that it could be really RPM or TDC sensor?????!
What else ?
I will control my fuel pump but the way the motor stops make me believe it is not a faulty pump that is the reason
My 340 000 km 89 V8 3.6 never failed like that!

Thank you very much ,
Best Regards
FredF

Hi,

sounds very like the flywheel sensor (RPM sensor).

Bastian

We had a problem like that with a 3,6 from 90,
there it was the coolant tempsensor.
The engine runs a few minutes, then it starts shaking,
then it stall.
After take off the plug from the tempsensor near the idle speed controler,
the engine runs fine when it has operating temp.

Hi,

isn't it the intake air temperature sensor you mention?

Bastian

yes. RPM and/or TDC sensors. Change both (they are a PITA to get at) and the car will run fine again.
That is a very common problem with the V8. Search this forum for "OT-Geber" or "Drehzahlgeber" and you'll find dozens of people who have had this issue.
part number RPM sensor: 077905381A, TDC sensor: 077 905381. price in Germany: 90,08 € (TTC) for each - they are in fact identical.

Thank you very much guys !

Do you know if the sensors that were mounted on the 87" 200 Turbo Automatic are the same , and the same lenght?
Because i have got two sensors that i did take in a junkyard some yeras ago.

Thank you
FredF

the Part-Number from the 200 is: 034 905 381
from the V8 is: 077 905 381

I think it's the same

Here it is:

Thanks !!

FredF

Hello Guys

I did change the TDC and RPM sensors......... a joke ! with a 4.2 and Cruise control ( 4 hours)But i did succeed.

I crank the motor , it starts......... i was happy ........ but the motor stops 5 minutes later.
So now for sure it is lnt the RPM or TDC sensors !.

So i did connect +12V directly at the fuel pump in the boot.I can hear the fuel pump noise and see the fuel come in.

Crank the engine , it dont want to start.

Have you an idea?
Thanks and have a merry christmas.

FredF

Maybe the Gasoline Filter in the Rear ??
Do you change him sometimes ??

Check in the Moment when the engineget out of run , the Spark ignition .

Do you have in this moment 12 volts on the Ignition Amplifters(Point 15) ??

Can you read the MistakeEprom (i dont now the Words in Englisch) ...

Put out the Oxygensensor . The black cable from the three in the same place how the tdc and RPM sensor are .


you have no conlog ???

Where do you come from directly ?? Near of germanBorder ???

@ Frank :
Maybe the Gasoline Filter in the Rear ?? I saw a big flow of fuel when i didconnect the fuel line , with 12V assigned to the pump
Do you change him sometimes ?? Never i did buy the car like that

Check in the Moment when the engineget out of run , the Spark ignition .
I was alone in the middle of nowhere so you are right i will try to see if the spark ignition is ok when a friend of mine willl crank the engine

Do you have in this moment 12 volts on the Ignition Amplifters(Point 15) ??
No i only put my DMM when the ignition key is on but the motor was not running, 0V on the ignition amplifiers

Can you read the MistakeEprom (i dont now the Words in Englisch) ...I did read it : Only RPM sensor fault code

Put out the Oxygensensor . The black cable from the three in the same place how the tdc and RPM sensor are . I dont understand what do you mean Franck I am sorry

you have no conlog ??? NO: no conlog

Thank you

FredF

The Oxygen sensor has 3 Wires .

2 in White (Heating)

and 1 in black (data to Eprom) . Take out this One Wire Cableconecting

The Spark-amplifter has an Thermofuse of the plate where the Amplifter is . check the Funktion .

The fault RPM Sensor is normally if the engine is not running .

Take direktly the 12 volts on the Spark amplifter . an show whats happen..after 5 minutes . Also look the elektrical Power when the engine runs ...from Start till the end ...ist there in the moment when get off also 12 Volts or more ??

My English is not so fine....in the past i must learn russian .....DDR...you now .

Change the Relais for the Fuelpump... there is an Safety logik inside ...when the engine stops in the same Time the Spark get off .

And you can take an other HAL sensor to test .

in the right Bank (zyl 1.4) you have an Hal sensor in the back of the Head .There are one connecting Plugin with 3 Wires . Change the kompletly Spark-Changer (Verteiler) ...

When i can stand in Front of your Car ...this was a Thing about 5 minutes for me.

Where do you came from ??? Iám from Heidelberg in Germany . To Strassborg i have 200 km .

@Frank
The Oxygen sensor has 3 Wires .
2 in White (Heating)
and 1 in black (data to Eprom) .
Take out this One Wire Cableconecting

OK i will do it

The Spark-amplifter has an Thermofuse of the plate where the Amplifter is . check the Funktion .

OK i will search for the thermofuse.I suppose if the car stops after a few minutes it's because of a thermofuse but i was unable to find it and to fix it

The fault RPM Sensor is normally if the engine is not running .
OK thats right i have read it on SJM

Take direktly the 12 volts on the Spark amplifter . an show whats happen..after 5 minutes . Also look the elektrical Power when the engine runs ...from Start till the end ...ist there in the moment when get off also 12 Volts or more ??

Do you mean directly connect +12 v on the sparks amplifiers ?
Do you mean to plug a Digital Metrix Meter on the spark amplifier ?

My English is not so fine....in the past i must learn russian .....DDR...you now .
My German is not fine too; i did study 5 years at school but was always seated near the window and the radiator ,

Change the Relais for the Fuelpump... there is an Safety logik inside ...when the engine stops in the same Time the Spark get off .
So you mean when i did apply +12 v directly at the pump the safety logic of the relay did stop sparks ?

And you can take an other HAL sensor to test .
OK but i have not another hall sensor, and i did read that with tue V8 motor if the hall sensor is out of order the the TDC take the same function ( Not on the 3B motor: If the Hall sensot is out of order the tue motor won't start)

in the right Bank (zyl 1.4) you have an Hal sensor in the back of the Head .There are one connecting Plugin with 3 Wires . Change the kompletly Spark-Changer (Verteiler) ...
Sorry i have no else verteiler

When i can stand in Front of your Car ...this was a Thing about 5 minutes for me.
I am sure........... and after that a 3 hours eating in a good french restaurant.

Where do you came from ???

South France: NIMES
My wife come from Strasbourg

It is a pity we are so far from each others

Thank you very much for your help, Frank.If that was a faulty old car or motor without electronics like Citroen DS or SM or CX , not a problem for me : Like you a few minutes and it's OK.

See you soon on trhe forum..... and i hope one day somewhere between Heidelbergs and strasbourg!

FredF