my engine rocks very noticeably sideways at idle causing the car to shake. I had a streetport w/3mm seals very recently. It idles steady at 750 rpm and the boost is constant at -12 psi vacuum. I checked the engine mounts. What else could it be? A mechanic says it might need a tune up. How do you tune up a Rotary?

 

Someone found out that the cable from the negative terminal of the battery to the car chasis is bad. This causes severe vibration. Try attaching a cable from the terminal to one of the chasis bolts that's unpainted to see if that helps.

If not, is your precat clogged? Is the transmission tunnel real hot from inside the car? That may indicate a clogged precat.