Re: Hi, I'm new here! (longish)

[quk@isham-research.demon.co.uk (Phil Payne)]

In message <E1C0A3EDDB0FD111A3030080C864228B268E32@BEELZEBUB> Matt Edmunds writes:

> Better mention my car I guess: a 1989 ur quattro (Lago Blue) numberplate
> F 757 GKP. It's all basically standard (although I think the a/c might
> be aftermarket) except for a Scorpion exhaust which the previous owner
> had fitted. It's been maintained by Dialynx for the last couple of
> years.

Wheee!!!!   Another missing MB comes in from the cold!

I have no record of this car on my databases.  I'd appreciate the
VIN number and engine number _VERY_ much, as this car should be right
in the cambelt/flywheel change area.

I shudder at anyone taking an MB to Dialynx, because Aelred simply
doesn't know how they work.  Arrange to take it to BR Motorsport in
Leamington Spa (I _know_ it's a long way) and ask for Martin to look at
it.

> There's currently a problem related to the turbo which will be looked at
> within the next couple of weeks (i.e. when I have time to take it to a
> garage). If anyone would like to speculate on the cause, I'd be
> interested. I think (hope) it may just be a sticky/knackered wastegate
> spring.
>
> Symptoms:
>
>  - Turbo feels slow to start boosting (compared with other turbo cars
> (not quattros) I have driven)
>  - If I floor the throttle in 2nd and accelerate strongly on full boost,
> there is much less power (lack of boost) when I change into 3rd
>  - Under full boost in, say, 4th gear up an incline, the boost appears
> to come in waves
>  - The engine occasionally suddenly cuts out at full boost
> (overboosting?). Obviously it's always when I'm overtaking something
> somewhere extremely dangerous.

OK - two points:

a) Your WOT switch is almost certainly knackered.  On a 1989 MB seen
   for the first time, I've stopped even testing the buggers.  Part
   number is 034 133 093F from Audi, or 0 280 120 308 from your
   local Bosch fuel injection specialist.  Cost is GBP38.50 + VAT
   from Audi, a lot less from a Bosch dealer, and even less from
   Tim on 01273 326189.  Tell Tim I sent you.

   That will almost certainly fix the sluggishness problem.

b) The cut-out problem can be diagnosed using the information you'll
   find on http://www.teleport.com/~scottmo/ecuf.html - don't forget
   that you must NOT turn the MB's engine off before pulling the codes.
   So the sequence is: recreate the problem, park the car with the
   engine running, and follow the instructions on the above web page.

> Oh for a boost gauge!

Doesn't tell you that much when you're diagnosing an MB, actually.  What
you need is a diode attached to the wastegate frequency valve and a duty
cycle meter connected directly to pin 8 of the ECU.  And a spare fuse.

--
 Phil Payne
 Phone: 0385 302803   Fax: 01536 723021
 (The contents of this post will _NOT_ appear in the UK Newsletter.)