[Author Prev][Author Next][Thread Prev][Thread Next][Author Index][Thread Index]

RE: intermittent power loss Update

Checked the voltage at the 02 sensor and it seems to fluctuate alot (from
about 0.2 volts to 0.9 volts). The WOT switch doesn't seem to do anything. I
have made up a little electronics kit which you can connect to the 02 sensor
shows if the engine is running normal rich or lean. I calibrated it so that
when the engine is idling the meter is in the middle. When the power loss
occurs the meter goes right over to rich which suggests that the engine is
getting to much petrol. Typically it takes approximately 5 - 6 minutes for
this to occur and it only happens when the engine is running at normal
operating temperature (90 C - 100 C). We have checked all the temperature
sensors and they all seem ok. Anyway since I haven't got much more to go on
I will have to bring it to the fourth mechanic on monday. Hopefully he will
be able to work out what the problem is. (He claims to have some special
computer that only Audi has, and he is pretty confident that he can fix it).

Once again thanks for all the help and when I find out whats   wrong I will
post it to the list.


'88 Audi 80 3spd 135 000 kms
'81 Audi 5+5 5spd 180 000 kms (so it says on the odometer)

> Chris,
> I am coming  in late on this thread but have you checked to make sure
> you are getting full throttle enrichment?
> One way to check this (and a good health check in general) is to hook up
> a DVM to the O2 sensor and monitor it while you drive around (I think
> you car has a O2).  It should oscillate from 0.4-0.5VDdc at idle (0.5
> Vdc is ideal mixture) and during light throttle cruising. When the full
> throttle switch is closed it should go to about 0.8-0.9 Vdc. This is the
> full throttle enrichment.  This could tell you if you power loss is a
> lean condition.
> Russ
> 87 5KCSTQ
> Littleton, CO