bottom end misfire with fault code P1587

dear forum  and a warm
welcome to you all,  here is my  first posting on the jaguar site . I am hoping the forum will be able to help me with my jaguar  3 litre sport 2002 Manuel that has developed a recent fault , I have recently purchased  the car and it has been  driving beautifully, but it has now acquired a bottom end misfire very prevalent on tick over but you can rev through it  with no further misfire throughout the range.I have a very good code reader and that recovered the fault code P1587 along with a orange light on the dash that has recently come on. I am quite competent with cars and I can fix most things so I decided to have a look to see  if I could identify something obvious  and on the right hand bank of plugs looking from the front I found the ignition coils and connectors for two of them had been taped on very securely with self amalgamating  tape  I am not too sure  as to the reason as yet its either possibly water ingress, which is unlikely  but broken locating tangs on coils or
connectors is more suspect. I have yet to investigate further  as I have  only just ordered a full set of coils packs
and replacement connectors and  I will solder them  in  once they arrive . The P1587 code  is pointing towards the throttle actuator control, I looked them up on a internet auction site to see what it looks like,  but I am not too sure if the throttle body
and  throttle actuator control  are one of the same part and can I change them separately ,and will another throttle body from another 3 litre fit may be  from 1999 to 2002 will fit and is this related to my misfire I am at a crossroads  on which way to go,  and finally I have down loaded the jag workshop manuals which were in a PDF format does  the hardback book format exist anywhere   as always best regards liam