[svxistentialist]

Jim,

You may be very close to the truth here. It is likely you have two problems; a fuelling or misfire one, and a driveline judder that is not related to the rough idling
[BTW, did you see my post on fault-finding on the Sensor School thread?]

If you have run the car in FWD, and the shudder is still there, but less than it was, then this possibly indicates a problem with the rear drive, maybe the u-Joint you mention. It would still be rotating, but causing less judder because it is not under power.

The FWD fuse is only meant to be used for short periods, as in testing. Randy ran his for a long time with no ill effects, but the short answer here is you are only masking a problem by taking it out, not fixing it. You still need to identify and fix this shudder.

Joe