Idling Problems on My Audi 2.6 V6 Avant 1997

[Razzman_Audi]

Hello, I absolutely at my whit’s end with my car (main reason being, I love it so much when it runs correctly!).

Issue 1

About 12 months ago the car developed symptoms whereby it would sometimes not start and if it did start it would immediately stall, but this was an intermittent problem and the majority if the time it would run fine. The problem however got progressively worse and more frequent. To attempt to solve the problem I had the throttle body stripped and thoroughly cleaned – this did not help. I then went on to replace the throttle control valve – this also did nothing! So approximately two months ago I replaced the throttle position sensor and cleaned the throttle body again, this has not corrected the problem! L
The car will be fine for days, then all of a sudden it will not idle. When I say it runs fine, when it is running it over revs (at about 1100rpm) on idle. The most frustrating thing is that my car is an automatic, making the problem almost impossible to live with.

Issue 2

The car has also developed a fault whereby the ABS light comes on (pretty much every time) when I hit 80MPH, the ABS is also starting to operate at slow speeds (under breaking) at about 5MPH for absolutely no reason!


CAN ANYONE HELP ME ON EITHER OR BOTH ISSUES??? :1zhelp:

Thank you

Adrian

[Crasher]

The idle is controlled by a valve bolted to the side of the inlet manifold, part number 078 133 455 D at £141.22 for an ABC engine, is this the part you refer to as the “throttle control valve”. You don’t mention if you have had a fault code read done, have you?

The ABS fault will be down to a wheel speed sensor suffering from poor sensitivity in both cases. That will have to be dealt with by a fault code read as well and if there are no codes, the output of each sensor will need monitoring at very slow speeds to see which sensor drops out just when the pedal starts to pulsate. The ABS will drop comms during diagnostics at anything above approx 15mph.

Is this an A4 or A6?

[Razzman_Audi]

Hi Crasher! Thanks for your input; you said "The idle is controlled by a valve bolted to the side of the inlet manifold, part number 078 133 455 D at £141.22 for an ABC engine, is this the part you refer to as the “throttle control valve”."
as i understand it yes, that’s what we replaced. I did have an ECU read done, but no errors on either the engine or abs are logged.....
thank you for your help, im really stuck here!! I need the help of someone who really knows this “odd size” of engine, I love my audi and amazingly today she got through her MOT, with these problems! The car is an A4 Avant

Thanks again

Adrian

[Crasher]

The idle being that high should have produced and error code so I think it would be a good idea to get another code read done on the engine ECU and the ABS at the same time.

[Razzman_Audi]

The code reads are giving me nothing at all, on the ABS or on the idling issue. Its my auto electrician that has done the code reading and although he isent an audi specialist, his equipment is compatible with my ecu as it is communicating with the car ok, but no errors are showing up.

Thanks again, adrian

[Crasher]

It is going to require some Live Data (or Measuring Blocks 08) work with the specs sprinted out to determine the idle speed problem and the same with the ABS speed rotors, watching their speed readings at very slow speeds (around 5kmph) to see which one drops out to 0 when the others are still reading.

[Razzman_Audi]

Im happier with the abs thing, do you know which haynes manual shows me how to get to the sensors and replace if required?

My major headache is this tick-over and apparent throttle control issue, is there anything else which could be causing this erratic behavior??

I am located in near leeds - do you know of anyone who could sort this without ripping me off? -I dont mind travelling!

Thanks again

[Crasher]

The ABS issue could become a scary one; I have known cars that have been virtually impossible to bring to a complete stop before running into something, albeit at very slow speed. In most cases I tell people to quickly go for the ABS off switch but if the particular car doesn’t have one…

I don’t use Haynes comics so I can’t help you there.

I know IVC in Leeds and they are good people but I am only just down the road in Nottingham a few miles off junction 26 so not that far.

[Razzman_Audi]

If your confident that you can bring this to a conclusion I will come and see your garage in Notts, please email me at sales@barair.co.uk

cheers

adrian