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

Re: "Ok, (peering around the cabin) who was it?"

>> Seems my 93 90CS has developed a case of the "rotten egg/sulphuric"
>Three main causes: 1) fuel with excessive sulfur content; didn't really
>believe it when a tech told me, but switching brands did help me once.
>2) one or both O2 sensors shot => overrich mixture, raw fuel into cat and
>resulting smell. 3) cat(s) is(are) shot; do you have any "death rattle"
>from below? Many of the early V6 cars had poorly-manufactured driver's side
>cats which blow apart right around 55k miles... BTDT.
>1993 90CS 70k miles

I just bought a '93 90CS Quattro(V6). It did this same thing on the full
tank of gas the dealer put in. After I had refilled it though, it went away.
Or at least so far.

I have another problem, though, that I thought might be related. When the
engine is cold, it has a misfire. Only for a couple of minutes. Once the
engine has run 2-3 min, there's no problem and it runs great. It starts and
idles just fine, but any application of the throttle drops the RPM, which
then picks up, but with a misfire. The RPM drop to me means its running too
rich (too lean would cause the RPM to rise), at least under these
conditions. With the sulfur smell, I suspected maybe it was running too rich
as well, but there are no "check engine" indications on the dash. Could the
O2 sensor(s) still be bad. What's the best way to determine this?

Rob Lloyd