Re. Fault code 2224 / MC2-engine

[Ben Swann]

Well this does not make sense - if there is an overboost condition, normally the engine
would be running like gangbusters and then cut the fuel.

The chip you have has been modified to allow an extended range of the pressure
transducer voltage beyond stock rating of 2 bar.  The stock cutout is around 1.55 bar
and a typical 1.8 bar chip such as the QLCC chip is programmed to cutout at 1.95 bar.
The 2+T chip basically extends the range a little farther, but basically works similarly
as many other chips.  The timing map has been adjusted to reflect the higher boost and
some other changes are in there.

This chip has been well tested and does not cause the problem you describe.  The ECU
may be throwing the code because it perceives an overboost condition and the question is
why.  The Manifold Pressure is measured at the port on the ECU.  There must be some
condition where the ECU sees a relatively high pressure, but the engine is not using the
boost or constrained.   Since the chip is designed to cut the fuel pump at somewhere
over 2 bar, then why is the engine  running sluggish?

Perhaps there is a restriction in the exhaust - still does not make a lot of sense.

Perhaps there is an electical component failing in the ECU and there is not really high
pressure at all, but the ECU is otherwise adjusting fuel and timing because it thinks
so.

I have not heard this problem before and would be interested in knowing what is causing
it.

You can disconnect/bypass the wastegate frequency valve (N75) and just run on spring
pressure alone.  If using the 1.8 bar spring then the pressure should peak at 1.8 bar
without assist from the WGFV.

What is the boost guage reading?  What is the digital readout in the instrument cluster?

Does the code recur after clearing?  Any other codes?

Ben


[Date: Thu, 30 Sep 2010 22:34:42 +0200
From: Dag B?sterud <dag.boesterud at consulgranada.net>
Subject: Fault code 2224 / MC2-engine
To: <quattro at audifans.com>
Message-ID: <000901cb60de$e9bff9f0$6400a8c0 at dagc22fb907b23>
Content-Type: text/plain;	charset="iso-8859-1"

I have been troubled with an engined that won't perform; it misfires and feels sluggish
over 4-4500 rpms. I have replaced all kinds of sensors, hoses, spark plugs; you name it,
I've done it.
Tonight I suddenly got a fault code; 2224.

2224 (Blink Fault Code), VAG1551/2 Fault Code Number 00544 Over boost condition(1989-91
200TQ, 1989-91 200T) UK MB engine. Boost pressure exceeded 1.6 bar for MC, 1.8 bar for
MB Waste gate or pressure hose, Waste Gate Solenoid/hose problem 

My ECU is chipped from Ben Swann.

Will this mean that my N75-valve is malfunctioning?

/Dag
1990 Audi 100 Turbo Quattro Sport Exklusiv]