project 4ktq problem found but unsure of fix...
audi at humanspeakers.com
Sat Feb 11 17:00:34 EST 2006
> 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
Sounds great. With the plate all the way down, there would be no fuel
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?
More information about the quattro