1994 940 non turbo. Read all posts, faq's concerning throttle body, vacuum leaks, etc. Before I begin servicing it here are the symptoms for consideration: starts right up cold or hot, when cold it will idle smooth at about 700 rpm for 30 seconds and then drop down to almost zero and go back and forth between zero and 1K. No black smoke. If I bring rpm's up to 700 using foot feed it will idle fairly steady. At stop light it will idle ok at first and then begin the rpm up and down. Car runs well and gets great gas mileage. Thanks.