Lead you were probably flying RR power a different animal to the JT9-7AH with a mind of its own if the bleeds are off or water/ice in the EVC vain control up and down and power shift all day long.
We would bring it back to part power trimmed the airplane and see how it behaved. At the same time requested decent say 360 to 320 dependent of weight and current altitude or a lower altitude off the FE chart once in the drift down. If the #1 didn't behave bring back to flight idle and leave it there. At flight idle if still mis behaving shutdown and advise ATC #1 shutdown and proceeding 3 engine normal operations and update you new weigh point times . At all stages trimming off the thrust reduction with right rudder ( ball in centre ) and bumping the remaining engines up a little on the power dependent on the weights. The SP would fly fine on 3 motors no need to panic grab another coffee and press on if you have the available gas.