The idle is getting worse and worse on my '88. I recently did a tuneup - sparks/wires/cap/rotor/air filter - and it didn't help. The throttle body was cleaned about a year ago, and the motor mounts were done about six months ago. Still it has a rough, slow idle that shakes the whole car, sort of like it was missing. At speed it seems to run fine, though maybe a little loss of power (its so gutless anyway it's hard to tell for sure). I'll clean the TB again just for good measure, but what else would make the thing shake like that? The oxygen sensor has about 60K on it, so it might be due. Would a bad oxygen sensor make the car shake at idle?