project 4ktq problem found but unsure of fix...

[Huw Powell]

> It was suggested to that I try to see if the throttle plate for the
> CIS was stuck and this is actually close to what the issue is....
> The throttle plate isn't exactly stuck but it is very stiff.
> 
> I pulled the intake boot off and the turbo inlet out of the way and
> tried to lift the plate by the center bolt using my small snap-on
> magnet  which is usually strong enough to lift large bolts and
> sockets, wrenches etc...   Well, the magnet actually had a difficult
> time staying on the bolt head and it took a couple of tries to
> actually get a good connection... 

Remember that since the plate is aluminum, all you're "grabbing" with 
that magnet is the little bolt in the center.

> I'd say that it is probably a
> 2-3 lb pull to lift the plate from it's resting position.   The plate
> will move through it's entire range but it takes some effort to move
> it, more than the intake of the turbo can provide I am sure...

2-3 lbs is not much - imagine if you had 1 PSI of vacuum in the intake, 
which isn't much.  The plate is a good 20 sq inches, so that would 
create 20 lbs of force on it.  When closed, anyway.

As someone mentioned, you are fighting residual fuel pressure when 
lifting it, too.

> If I wedge the plate up a little the engine will idle and rev up
> until it runs out of fuel and if I work the throttle plate and tb
> butterfly simultaneously the engine will rev up and run beautifully..
> but if the plate falls to it's resting position the engine instantly
> dies...

Sounds great.  With the plate all the way down, there would be no fuel 
at all.

If you feel like tinkering a little bit, put it all together, and place 
a 3mm allen wrench in the adjustment screw in the middle.  Then crank 
the engine, you should see the wrench go up a little as the plate rises.

Now, as I remember, it was finally running "well" until you pulled the 
glovebox... I know you checked everything out in there, but maybe it 
should be checked again?

-- 
Huw Powell

http://www.humanspeakers.com/audi

http://www.humanthoughts.org/