Rev happy gremlins in my Audi

[TheWills]

1996 A4 Avant 2.6.
Came to drive home to find the car had a flat battery. Jump started and it revved up to 2200 until I blipped the throttle, it then dropped to 1800 but pulsing like a boy racer at the traffic lights, up down up down between 1800 and 1900?. On the road it is running away at higher than normal revs and when the clutch is dipped it revs up to 3000 and then drops to start pulsing again. It also suddenly drops the power for a moment when trying to cruise almost as though I dropped from 4th to 2nd gear and then it picks up again. The brake test does not function, just shows the caution from start and I know the pads are good.
As for the flat battery, I did find the rear passenger light left on by my little girl, but it is showing 14V without the engine on and 17V when driving.
Thats all I can think of to best describe my sudden problems, so please, please, any help is greatly appreciated. PS no VAGCOM to plug in.
Cheers Dave.

[TheWills]

Does this sound about right to anyone?

Idle speed which is either fluctuating or excessive
Cause:
The idle speed components are lacking electronic adjustment after a voltage loss in the system (for example after the disconnection of the battery, control unit change and a problem with the voltage).
Models affected: ABK, ABC engine
Service:
Referring to the workshop manual do a basic setting with V.A.G 1551 . Throttle valve potentiometers and idle stabilisation valves have been unnecessarily changed too often because of lacking system adjustment. If the complaint is not corrected with the basic setting, then a component is defective. It must be located by referring to the workshop manual.

[TheWills]

Dropped the car off at the local garage this morning (new owner, so can't vouch for his experiance), explained all including the above, he called me back just before closing to say that there are no error codes on the car at all, all sensors are fine. He then tried to access the ECU, but he is saying that it is blocked. He is keeping the car to have another go at it in the morning, he isn't going to charge me so good stuff. Could it be that it is only possible to access the ECU with certain equipment or specific coding, I couldn't say what he is using as I didn't think to ask.

[mrjolly]

sounds like an air leak to me.??? old fashioned thinking.

[TheWills]

Well just got the call to come and pick the car up, they tried as stated above to reset the ECU to no avail, took the car to another guy who has better diagnostic kit, no joy, the car said ECU blocked no base settings.
A few phone calls to colleagues in the trade and finally a call to the help desk of an ECU refirbishing company and a few miles on the car and £20 fuel put in and the verdict is that it can't be reset on the early A4 ECU as it sets it's own parameters based on your driving style, which can take as many as 100 miles depending on how flat the battery was/the amount of info lost. So the bill is £70 and I have the car as it was when it went in, with the exception of having a clue as to what to expect over the next few days. So I'll give it a carriageway cruise, do some traffic, blip it a few times in between and see how it goes.
Don't you hate shelling out to find out if you need to shell out more dosh or not

[TheWills]

It worked!!
Did 34 miles and switched the car off, came back and it settled straight back into 700 idle and behaving itself on the road, awesome