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Re: Irregular 320i idle



> From: Michael Christofas <st92exwm@domain.elided>

> 	1. When the engine is totally warm the idle raises up and down.
>  	   If i bring up the R's to say 2500 It still deviates??? I sus	
> 	   pect the ecu? My ques is can I Use a fuel distributor say from
> 	   VW cis, or disconnect the push valve and readjust the CO?, or 
> 	   Where and how much is the ecu???

Number one, check for vacuum leaks in any of the vacuum hoses, pcv hose,
etc.  Air leaks can give the system fits.  Second, check that the O2
sensor is still working.  You can do this with a Digital Volt Meter (DVM). 
Make sure the O2 sensor voltage is swinging between ~0.2 and ~0.8 volts. 
How much does the idle varry, a few hundred RPM or a thou. RPM?  There are
a some other things to look at but it depends on how much the idle is
swinging and how the car runs otherwise.  There are a few good books
regarding tuning and troubleshooting K-Lamda system (Randy Probst book 
is pretty good).  The system is really pretty simple. 

Regarding using a VW airflow meter, aparently older VWs used an 80mm air 
flow meter while the later 320i's used a 60mm meter.  My early 320i uses 
the 80mm meter.  You may get a slight performance improvement by going to 
the 80mm VW meter.  I would use a VW meter with the frequency valve so I 
could keep the Lambda control if your car is only a street car.

> 
> 	2. I also have the hard shifting others experince on the net. 
> 	  nobody seems to give there formula for cold weather. The owners
> 	  manual say hd motor oil can be used in cold climates. I used 30w
> 	 I helps a litle.  Any body have a tried and true formula???

Try changing the transmission oil and use Red Line MTL synthetic 
transmission oil.  MTL is just great stuff.  It cured my 320i's hard 
shifting. 

*******************************************************************************
Walt Barie (wgbst4+@domain.elided, barie+@domain.elided)
Graduate Student
Dept. of Electrical Engineering, University of Pittsburgh

'79 320i DSP Solo II Car
'80 528i
'80 Volvo DL (temporarily:)

Of course what I say in no way reflects the views of the University....
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