[urq] Still running very rich.

Buchholz, Steven Steven.Buchholz at kla-tencor.com
Tue Dec 12 13:43:49 EST 2006

... back when I was a rather new urq owner, and the dealers actually knew what an urq was ("Oh, a *QUATTRO* quattro!"), a service manager told me that the urq was "cold blooded" ... because mine was not running well until it warmed up.  They do tend to be characteristically this way, but there are things that can be done.

The big things that I don't see in your report on what you've done ... have you checked the fuel pressures?  The system and control pressures dictate the mixture ... so if the engine's running rich I'd look to see if the control pressure was low for the temperature.  The other thing I'd look for is whether or not the OXS Freq Valve was running.  On my car the driver for the OXS Freq Valve doesn't always start working from initial start up, and so the engine will run poorly.  In my case the engine idles, but if you take the throttle off idle the engine will either die or start to backfire.  This one is an easy one ... start the engine and listen for the OXS Freq Valve buzzing ... it is located near the turbo side front strut tower just below the hood line.

Steve B
San José, CA (USA)
> I'm still having the very rich condition on my 83urq from start up to when
> it gets up to temperature. Here's what I've swapped  so far with no  change.
> ECU, wires, cap, rotor, plugs, frequency valve, checked the air temp  sensor
> and
> the throttle body switches. The car starts ok even though it will  stall
> unless I keep my foot on the gas. The cylinders were black, sooty,  and wet
> with
> fuel when I checked the plugs. I have to punch it a bit after start  up to
> clear out the cylinders. It also runs ok, but the rich smelling smoke
> emitting
> from the exhaust is a bit noticeable. I can rev it without the 4k cut  out.
> Ideas? I might just say the hell with it and get  034's full Stage IIb
> package.
> Any BTDT?

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