Hi I posted this on clublexus too, but trying to get some more opinions. Ihave a 92 sc400 without about 130k miles.
It runs super strong 95% of the time, but I've had an intermittent misfire issue. The idle is rough enough to feel the car shake. Also I can get it up to speed okay, but the car will fluctuate between bucking/hesitating, with random surges of power.
It seems to do it the most often when the car sits for a week or so. If I drive it regularly it doesn't seem to happen as much. However today it randomly decided to do it. But then I go back outside an hour later and it took it for a drive to have it run full power again.
It's had a full tuneup: plugs, wires, caps/rotors, coils, etc. The injectors and fuel filter are also new. Good compression. I'm stumped, and not sure where to go from here. There is also no check engine light.