ECU Failing on 20v CQT??

[Mike Arman <armanmik@n-jcenter.com>]

>
>Date: Tue, 6 Apr 1999 23:01:42 +0100
>From: "Karl Harrison" <karl@harrison.prestel.co.uk>
>Subject: ECU Failing on 20v CQT??
>
>I've been having a few problems with my 91` CQT and my local Audi Guru says
>my ECU is reluctant to save its settings and my problems(idling variance
>plus erratic power loss) may be due to a faulty ECU.
>
>Can anyone whose had ECU problems give me some feedback on what problems
>were experienced?
>
>How much is a new ECU for 20v CQT engine type 7A?
>

To answer the last question first, at the very least, a million dollars.

I'd try a substitute ECU before I did ANYTHING else - remember, the Guru is
guessing, but YOU are paying!!!!!

If the ECU is reluctant to save the settings, this sounds very much to me
like a failing EPROM - this sometimes happens with EPROMS in computer
BIOS'es - replacing the chip solves the problem (although most of the time
it is the CMOS battery that's bad).

The EPROM is soldered in, but it is not a real big job to unsolder it, put
in a socket (28 pin DIP, usually), and plug in a new chip (probably a
27C64). The real trick here is to obtain a copy of either the stock code
(can maybe read this from the old chip) OR just add a performance chip -
plug and go. (You'll need an EPROM burner or access to one.)

A little arcane, but a few hours fiddling around sure beats buying a new
ECU, and if you're looking for a good excuse to buy a chip anyway . . .

Best Regards,

Mike Arman