Page Updated 10/19/2005

Broken Wires and connectors

We're trouble shooting a rough running 4000Q with a MC-1 turbo in it.

It crapped out on the way to V.I.R. in Long Island, NY.

Ran FINE the day before, slight miss at highway speed was it.

This is where I sprayed starting Fluid to get it running.

Hmmmm, nothings holding the igloo on, and the way it faces leaves no wiggle room.

Unmetered air was probably getting in. 

>>> CHECK the igloo cooler top EVERY time it backfires! <<<

Probable solution HELP:

I'm browsing Audiworld.com 4000 forums and this info comes up:

Might be the E-Test sniffer pipe?
User account number (aid):
Posted by Katman on 2005-10-18 09:49:47

In Reply to: 4000cs quattro header pipe posted by snickers on 2005-10-18 08:03:55

"Comes from down on the exhaust somewhere, and is clamped to the intake, and has a grey cap on it?

If so, that pipe is there so it's easy to sample the exhaust gas ahead of the cat, for setting up the CO levels.

If the wires are brown, and bolted under the same clip as the end of the pipe, they are the ECU ground wires. VERY important that that ground connection be clean and good!

I've never seen one of those pipe assemblies that was ever complete and working. The bottom connection usually gets dumped first time the exhaust gets replaced..


It turns out in this photo, I actually undid this ECU ground, cleaned the ground contacts (on the IM)

and loosely grounded them in a test run when the Fuel DPR was "re-wired". 

At first the car wouldn't run...now I know why, ECU ground was poor.

When I reconnected everything correctly, the end result was a running car.

In hind sight my test run was flawed (no start) because I didn't properly

reconnect the ECU ground... ONLY undo one thing at a time!

After it got dark, the uncle shows up and sees it arcing to the shroud.

Cleaned the cap and rotor, new plugs gapped to .028 (specs 0.25 -0.35)

Change the fuel filter, get it run around 3,000 Rpm and get it home.

When at home I can tinker a bit more.

Took the carb cleaner (they recommend Fuel injector cleaner) and clean the ISV.

The P.O. in the swap let this just dangle. 

I replace the hard line from the plastic 90 to the air box (under ISV)

The was the orientation, I had to turn the three way rubber

adaptor and replumb to keep the new hose from kinking.

New orientation above.  I flipped the adaptor so it bowed upwards and moved

the crankcase connection from the center to the end fitting.

I gasket sealed the elbow fitting into the igloo for an airtight seal.

This is a before orientation and photo to remember what went where.

I think I found the problem:

I've been focusing on the DPR Differential Pressure Regulator.

(The car has a similar symptom I've experienced before traced to this)

This controls pressure on the top and bottom of the fuel distributor.  I had one fail.

I can Ohm meter the value across the two terminals (the connector boot is marked 1 & 2)

If open circuit or Infinity reading the gizmo is no good.  460 Ohms is spec I think.

You want a steady value in other words.

Here, I'm trying to figure out how to pull out in internal connector to replace the wire.

Scroll to the bottom of the page for how to take these apart.

terminal 1 is the RED and YELLOW wire

terminal 2  is the RED and WHITE wire

The connector is part number: 025 906 231 two pins connector for the DPR on the fuel distributor.

Audi of Nashua NH said their ETKA shows this number supercedes to 443 906 232.

which I believe to be # 1 - 2, in the above diagram they faxed me.

27/28, 29/30 and 39/40 look similar, but aren't the ones for this application.

$10, make sure you get the internal tabs / wire connectors.

This connector seems to match up on the Harness page of ETKA 5, as #16.

Hopefully, fixing this solved the rough running and no idle / stalling.

AMP connectors


Left locked in place, Right Unlocked to slide apart, press wire with thumb.

inside these tines grasp the male terminal connectors

On the connector ends, there is a tab to depress.

Shown below in the middle, to be depressed

to allow the connector to slide out from the plastic housing.

$ome special tool does this, but it looks like a paper clip could do the same thing?

Here's a similar connector as an example.

Revised part 443 906 232

Here's the winner: 1& 2 on the newest version ETKA sheet Ill., 970 - 20.

ETKA 5 didn't have this connector page listed.

Old connector had a Plus internal to unlock the wire ends

The new wires are $9 at the dealer EACH under the connector above.

Don't freak the new connector doesn't have a center terminal.

This new nifty tray slides right in to set the center terminal height.

Look through from behind.



Inserting a wire will cause it to lock in place by the tabs.

Below here is how the tray slides in.  Upper flap closes when try is slid in to lock the wire.

Push it in too far and it'll lock and you'll have to undo it.  DOH!

Side by side.  Old vs. New.

Remember this 4000Q is a MC conversion so the throttle

position sensor isn't an issue on JT engines.

Make extra sure NOT to cross the 1 & 2 terminal wires.

I crimped the wires with a but splice innards.  I removed the outer plastic covering.

I later hit both ends with solder to sure up the fit in the connector splice.

Shrink wrapped and rerouted under the fuel injection lines.

It started and leveled off at 1000 RPM  I was stunned. 

The ground to the Intake Manifold (IM) is critical too.

They are the two other brown wires of the harness lead to the AMP connector on the DPR.

Its running right after the repairs!  Yippe!

Differential Fuel Pressure Regulator:  DPR

The older ones have no adjustment screw. 

Just two ports to the chambers in the fuel distributor.

I can Ohm meter the value across the two terminals (the connector boot is marked 1 & 2)

If open circuit or Infinity reading the gizmo is no good.  460 Ohms is spec I think.

Back to 4000Q index    Back to Quattro123.com Main Page