SW2 Idle Problems

I have a 2001 SW2 with 30k on it. Recently I've been having
intermittent idle probelems. When the car is warmed up and driving on
city streets with stop and go traffic, the idle sometimes jumps up to
1500-2000 rpm. As soon as I put it in gear and let the clutch out, the
idle goes back down. When the idle starts going high, I can rev the
engine high once or twice and the idle goes back down to the normal
900 rpm. This problem has been happening more and more frequently. The
interesting thing is that when this is happening, I can turn the
engine off and back on immediately and the idle will then work fine
which I would think indicates some sort of electronic issue. Any
ideas? Anyone else experiencing this?

Thanks.

KH

 

I had this problem on my 98SL2 at around 48K, and I've seen others
mention a very similar problem.

In many cases it turned out to be the _throttle body position sensor_.
If you take it in they will probably want to change things like the
coolant temp sensor, etc. Get them to check the TPS first. It took me
about 8 trips to the dealership and nearly as many sensors/switches/etc
changed within about 3 weeks before they figured it out.

Let us know, I'm curious if it is this or something else.

On a side note, I have to say, this very specific problem seems to be
appearing often enough that I'm a little surprised there isn't a
technical service bulletin on it. (Or is there?) Does anyone know what
the critera for issuing a TSB is?

-rj
98SL2