I have a 98 S70 GLT with 96K miles. Sometimes while driving in suburban chicago traffic and thirty five, or forty five mph, the engine will suddenly go to zero rpm's for perhaps one second and will then resume running normally. On one ten mile trip through heavy traffic it did it eight times. Yet, later that day on the return it did not do it. No check engine light, btw.

It will also do it while idling at a light, or driving slowly, say at five mph. Just this evening, it did it at five mph and the engine did not come back to normal rpm. I had to stop the car, put it in Park and restart it. Restarting the car is normal and fine. In between these odd situations the engine runs smooth as can be and has plenty of power.

Unrelated? to this, two weeks ago, my ignition switch started giving me a lot of resistance as I turned it to start the car. That lasted about five days, but now it's smooth and easy to turn, just as always. About a month ago, I got a lean burn message on the computer, but had the injectors cleaned by a local shop that sprayed a cleaning fluid through the throttle body for half an hour. No recurring computer message.

Has anyone had this happen? What was it and how did you fix it?

thanks,

bob.