So I have a 1993 960, and the last few days it has been surging from like 400 to 1000 Rpm's whenever I come to a stoplight while the engine is still warming up. (it hasn't been much warmer than 10 or 15 degrees the last 5 days) If I put it in neutral it will go away --somewhat-- once the car is warmed up though, everything goes as it should. I had a check engine light on earlier this week, and the code had to do with the oxygen sensor, do you think this may have something to do with the problem?

 

It could be.
When you can try cleaning the throttle body.

 

I've ordered a new O2 sensor, and am going to replace that first and see if it makes a difference. How would I go about cleaning the throttle body? The engine is still pretty fresh ~25,000 miles on it...though since july I have logged about 11,000 miles. (A good 500 of them have been on mud and dirt roads too) So perhaps it is due for a cleaning?

 

Ok, after searching around I found out how to clean the throttle body. Pretty simple. So I took everything apart and noticed that a) there was a small pool of oil sitting on top of the intake pipes. b)there was a small amount of oil around the top of the throttle body, and sitting down in the bottom. and c) One of the two small yellow colored hoses that goes from what looks like some sort of one way round valve on top, to the bottom of the body, was disconnected. Anyone have any thoughts on this?

 

Can't picture the hose at the moment.

Also make sure the flame trap is clean and the hoses going to it.

 

I'm trying to upload a few pictures, but I keep getting "error saving file to disk". I have 3 pictures, each about 100k in size, and in JPEG format. Am I missing something?

 

Might be to big.
You can host them on Photobucket.com then use the Image in the top right of the reply then paste the link.

 

ok I uploaded 3 pictures to Photo Bucket. The first one is of the disconnected hose, second shows where the oil puddle was, and I'm wondering if you can see where the flame trap is in the third one. Today when I pulled out of the garage I noticed that there was about 4 or 5 quarter sized drops of oil on the floor. I'm really hoping that it was just oil that ran down into the skidplate after I cleaned it off with brake cleaner...because if it's a major leak I'm going to be really [:@]!
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The pictures are a little small but looks like the hose you have circled is the Vaccum hose for the fuel pressure regulator. It just goes down to the Vaccum tree on the intake.

The Flame trap is where the second white hose goes to. Also it is what the Hose clamp is clamped to.

 

ok, the flame trap seemed clear...though it was rather oily. How would I go about taking it off and cleaning it?

 

Just remove the entire plastic piece and clean with brake cleaner.

 

ok, flame trap was clear, but I cleaned it anyways just to be safe. I also started the car without it installed just to make sure that the hose wasn't clogged.....it definately wasn't. Now that I've done this and cleaned the throttle body it runs a lot better, and doesn't stall out/fluctuate when I come to a stop. Today I'll get that o2 sensor installed and it should cure my semi rough idle (jumps maybe 100-200 rpms right now). Hopefully then I'll be in business. The part is due in this afternoon, so I'll post up once I get it installed.

 

wow, 260 bucks later the o2 sensor is in, and the car is running damn good. I can't even feel any vibrations through the steering wheel. I love it. In addition to the new sensor, I think the TB and flame trap cleaning have really helped in making a difference. Thanks for all the help tech.

Thought I would post a pic I took of it when I first got it a few months back. I just washed it yesterday, and after 11,000 miles in just over 6 months, she still looks just as good.

 

Glad I could help.