re. 5ktq emissions woes

[Doyt W. Echelberger]

Owner and Ben say say the car is running rich. OK, check out the O2 sensor,
'cause at 94k miles it is past it's 'change mileage' anyhow, and lazy O2
sensors result in rich mixtures.

Look at the way the crankcase breather pipe fits at its bottom end, and
look for a soft rotten spot at the first bend in the rubber hose.

Pull out the washer bottle and feel all along the vacuum hose between the
lower WG chamber and the intake manifold. That hose gets a lot of heat and
hardens up and crumbles, leaving only the fabric cover to fool you into
thinking it doesn't leak.

And pull the plugs, look at them, and probably replace them with
factory-recommended plugs.

Replace the rotor and cap. Check the fit of the wires that go into the
dizzy. That grommet that they go through may be loose and maybe it is
letting the wires move around relative to the dizzy body. Check it out.

Run a bottle of Techron through the tank and get those injectors cleaned
up. Then change the oil & filter before you go in for the test.

And remember what Scott Mockery found out about the throttle
switch.......every switch he examined that was an original had
microfractures of the solder joints inside the switch. If you are driving
an 86 5ktq with an original throttle switch, the switch is probably faulty
and you deserve a new one. And it has a lot to do with how the car idles.

Go in with new fuel in the tank. Some folks use alcohol-laced fuel for the
week of the test.

And warm it up really good just before going in.

Doyt Echelberge
87 5ktq  in Ohio  USA



 >>>>>>>>>>>>>>>>>>>>>>>>>>>
At 10:37 PM 7/28/2002 -0400, you wrote:
>To: quattro at audifans.com
>Cc:
>Subject: 5ktq emissions woes
>From: qshipaz at juno.com
>
>Greetings,
>
>The hangar queen ventured out of the hangar these past two days, boldened
>b=
>y the temporary tags, hoping to get legal.
>
>-- I thought I's throw in my comments since I saw no one else replies as of
>yet.
>
>Patient is an 86 5ktq. Hasn't been registered since 12/99 in California,
>wh=
>en it passed Cal emissions easily. I admit I have not done all the
>requisit=
>e filters yet, although the LOF has just been done. 94K on the (working)
>od=
>ometer. In AZ, a Quattro doesn't have to pass anything but the idle test
>(h=
>ow would you dyno one??) and the equipment check (which it passed- car is
>b=
>one stock, so far)
>Idle readings were 363 ppm HC and 7.45% CO! Standards are 220 and 1.20%.
>
>-- Well it is running rich.
>
>Clearly something is amiss. Fuel is mostly Chevron premium (but I can't
>vou=
>ch for the age of what was in the tank before- probably no more than a 1/4
>=
>tank. And the car was driven around the neighborhood fairly frequently by
>t=
>he MBZ/VW shop owner who previously was the TQ's custodian. Could this be
>e=
>ntirely due to the fuel?
>
>-- not likely
>
>Thinking of Phil: "Don't guess. Pull the codes." I did. Tried twice, and
>ge=
>t 4444, as well as a smooth idle at 900 rpm, only about 1.1 bar boost
>thoug=
>h=2E I attribute this to the fuel quality waking up the knock sensor. O2
>se=
>nsor is my next guess- but wouldn't the code come up if that were the case?
>
>-- No, the Oxy sensor does not provide any feedback to check itself, nor
>does the system have capability to determine it is giving a false reading.
>
>I am aware that there are many possible factors here. IME, messing with
>the=
>  CIS mixture screw only produces a foul-running car if you do not have a
>"s=
>niffer" to check the emissions while you do so. So what am I missing? I
>cou=
>ld just bring it to the shop, but I've gotten away from that for every bit
>=
>of mech. work I've done on the Q or the Z-car in te last two years. Surely
>=
>I can figure this out- idle testing only can't be that hard a goal to
>shoot=
>  for. Any BTDTs will be much appreciated.
>
>-- You most likely have a vacuem leak, perhaps among other things.
>
>Last thing- there is a crack in the downpipe, behind the turbo, at the
>fact=
>ory weld. I realize this is serious, and will be replacing it very soon,
>bu=
>t I don't think this negatively affects idle emissions- or does it?
>
>-- Yes it can, but what I found after doing mine is that the hairline
>fractures were not affecting performance or emmisions as much as I had
>thought.  The addition of air or leaking out of exhaust can throw off O2
>sense readings a little, particularly at idle.  A serious leak, that is one
>you can hear and smell will definately throw off the mixture and cause
>driveability problems as well.
>
>Before everyone jumps at me for not methodically giving it a full tune-up,
>=
>T-belt, all fluids- think of this. I have driven the car approx. 20 miles
>b=
>efore today. I have a bit of a philosophical problem with pouring hundreds
>=
>of $ into a vehicle which currently has only a temp. tag and an open out
>of=
>  state title. I can't get title or registration until I slay this
>emissions=
>  dragon. Just a thought.
>
>-- Tuneup is always good, as it provides a baseline and tends to help rule
>those  things out when troubleshooting.
>
>Quattro Kool-aid: I had fun on the freeway today. Haven't run a turbo 44
>on=
>  the highway in three years! The corkscrew ramps at double the posted 25
>we=
>re great. This is my first Quattro though I've had two other Audis- well
>wo=
>rth it. But you guys knew that already... BTW no driveline vibes and the
>di=
>ff locks work. At 94K, this is a low-mileage 5ktq!
>
>-- Yes, but enough age and mileage to assure the vacuem line you replace
>will fall apart as you remove them.
>
>Regards,
>Rob
>
>-- Hope this helps.
>
>-- Ben