[V6-12v] C4 100 new owner questions

[James4ihl at aol.com]

I didn't get the original message to this thread, but as far as I'm aware, a 
'94 model car would no longer have a manual CO adjustment screw, as by then 
the ECU had taken over 'adaptation' of the O2 sensors. The only way to perform 
adaptation after around 06/92 was via VAG1551, or similar (e.g. VAG-COM). In my 
experience, it would be very unlikely for the car to fall out of adaptation 
once set. It's far more likely you have a problem with a sensor or some kind of 
intake air leak. I just cured a hesitation by replacing the O2 sensors, but I 
also replaced the 2-pin temp sensor (the one that feeds the ECU, it sits on a 
water pipe behind the engine on the right hand side of the block as you look 
at the engine bay from the front of the car - not to be confused with the 
3/4pin sensor on the left under the ISV that, as you rightly say feeds the dash 
and the 2-stage fans). It's basically worth checking the 2-pin coolant sensor, 
the O2 sensors, the MAF sensor, any air leaks/obstructions, any possible fuel 
delivery problem (blocked fuel filter/line/dodgy pump/relay/fuel pressure 
regulator, etc.) or any misfire (faulty coil, spark plug/plug lead). Well, the 
problem with 'hesitation' problems as I found along with the rest of this list, 
who kindly helped me, is that it can be caused by so many things! Can you be 
more specific about when the problem occurs?

James
In a message dated 29/6/04 7:46:41 pm, Lt.Kubosh at atlas.cz writes:


> Ad 1) The car hesitates on acceleration.
>     I do not know if the '94 model has the MAF sensor with or without the CO
> adjustment screw. If the CO screw is out of     range the car hesitates.
>     If the hesitation happens only when cold you may have dead O2 sensors
> heating
>     I remember the user few years ago who had problem with acceleration 
> caused
> by water temp sensor. (You have to     check the right one. There is second
> which is used for dashboard gauge - has nothing to do with engine.)
> 
> If you have something like vag-com you can find useful my page. There is
> table with value ranges for the engine.
> http://www.44magnum.czweb.org/en/audie.html
> 
> Good lick
>     Martin