Might benefit someone else but another useful piece of info I came across
regarding the Audi VW digifant motors is a common problem with a dry solder
joint in the ecu voltage supply relay (located under the steering wheel dash
(part No. 165906381 & about £10 from main dealers). This causes misfires or
cutting out problems. I read if the relay is black it's the unreliable one
made in Malaysia (or somewhere) and best to change it for the more reliable
bosch light grey colour relay.

"dave AKA vwdoc1" > wrote in message
...
> congrats and thanks for posting the solution! ;-)
>
>
> "Redwood" > wrote in message
> ...
>> "Redwood" > wrote in message
>> ...
>>> 1993 Audi 80 2.0 single point (ABT engine).
>>>
>>> It's my dad's car, had it from new & been well serviced over the years.
>>> I'm trying to diagnose poor top end performance and thinking it may be
>>> the
>>> lambda sensor, or any other suggestions welcome.
>>>
>>> Starts & drives well but gutless at top end. Up to about half throttle
>>> it
>>> has plenty of pull but put your foot down for overtake or approaching
>>> inclines and there isn't much there and takes a long time to build up
>>> speed - usually have to knock it down the gears. Feels as though it
>>> wants
>>> to go but a lack of fuelling at top end is holding it back. In fact if
>>> your cruising along say at half throttle and plant your foot down it
>>> feels
>>> like it actually slows down before very slowly starts to build up speed.
>>> TPS & various other sensors appear ok (within Autodata spec) & checked
>>> for
>>> any vacuum, air leaks. The injector unit to manifold rubber flange
>>> looked
>>> a bit worn & cracked but I've replaced that.
>>>
>>> Only thing I can think of is the lambda sensor as the cars done about
>>> 120k
>>> miles on the original so was wondering if that could be on its way out
>>> and
>>> slow at sending the correct signal to increase fuelling at top end?
>>
>> Well it did turn out to be the lambda probe. Went for MoT yesterday and
>> it
>> failed on high emissions (0.5). The lambda passed but garage man said it
>> was
>> sluggish. New probe fitted and emissions passed & the car is running
>> loads
>> better with now plenty of pull at top end. Previously if you tried to
>> hold
>> the revs at a fast idle it would pulsate down & up slightly but now it
>> holds
>> steady.
>>
>>
>>
>>
>
>