what can "destroy" the lambda probe?

Hi,

for several weeks I have always this strange problem:

When I get my car (306 1.4, built in 1995) back from garage it works
fine for several days, then one day with light problems (bumpy idle
running) and after this I have huge problems (bumpy idle running then
cut off). In the past we don't what may cause this problems it was just
strange. But last week they made an exhaust test and it fails - they
changed the lambda probe 3 weeks(!) before... So they said: ok, we will
built in a new lambda-probe. Exhaust test was okay (co: 0.00, lambda:
1.07) and everything was fine for 4 days and today I got the first signs
of the same problems: bumpy idle running up to cut off. I drove to the
garage again, they made a exhaust test again: didn't pass.

What the hell may cause this? This must be the injection-electronic, I
fear... Can somebody tell me, what may cause this problems? Hopefully
it's some cheaper stuff... Lord, I pray it's not the injection-electronic

A sidenote:
For several month (I have the problems with my cars since september
2003), the controllight for the lower-beam headlight was only glowing
after several minutes (the headlight was on, but the controllight not).
I never really worried about this, because I thought it's just a defect
cable, but after I got the car back on monday, the controllight was
glowing always when I turned the lower-beam headlight on. Even when it
was cold (last night -15° celcius). But when I started to drive back
from work today, the controllight was _not_ glowing, after I turned the
light on. I saw this and thought "oh my god... the engine problems
again?" and it was so: bumpy idle running up to cut off. I know this
sounds strange, but can this be related in any way with this engine problem?

Thanks for any hint...
Jens

 

poor idling cna be caused by a number of things but most common on the 306
seem to be the stepper motor and coil packs. Can you explain what you mean
be headlight control light?

Simon

 

Hi! Thanks for your response... Nope.. It's not the stepper motor and
not the coil pack. As I wrote it's the lambda probe. I try to figure out
which may cause all this "destroyed" lambda probes. After changing the
lambda probe everything is fine, but only as long as the new lambda
probe is working. But it works only for some days then it seems to be
damaged/blocked/whatever. After changing the probe, it works fine for
another several days and so on.

Uhm, what do _you_ mean? _I_ mean the controllight if the headlights
are turned on or not. If you switch the headlights on, this controllight
should glow. In my case it does glow, but only after several minutes the
lights are turned on. But this delay seems to be _only_ when I have the
trouble with my engine. After my garage changed the lambda probe, the
controllight glows directly after I turn on the headlights. For 4 days.
Since today I have the problems with my engine again and the
controllight glows only with delay again. Because I'm going crazy with
the problems of my car, I'm trying to check if there may be a link
between this two effects... Is there any kind of central electric _and_
electronical controlsystem?

Jens

 

hi

so by control light you mean the one on the dashboard instrument panel i
assume. (green when dipped, blue for full beam)
You've ruled out the stepper motor and coil packs (by what means?) Is it
possible the 2nd lambda sensor was faulty (it happens)
high lambda reading may not be becasue it is broken. just it is reading
high. i had a high lambda reading once on my diesel. The fuel mixture was
over rich and dirty air filter.
Maybe the light problem is causing an electrical problem which is causing
the ECU to over richen the mixture. If you disconnect the battery for a few
hours and clear the ECU memory you may find the lambda value is back to
normal. try it after the car begins to idle bumpy again.
worth a try i think.

 

Hi!

Of course!

The stepper motor was replaced in december of last year and the
sparkplugs were checked too. What do you mean with coil packs? I'm not
natural speaking english, sorry Do you mean the spark coil? This was
replaced by a second hand one.

Hm.. what causes the over rich fuel mixture? Only the ECU, am I right?
Or maybe the ECU with some kind of electrical problem as you suggested
beneath?

Thank you for the hint, I will try it. Nothing to lose, you know

Jens