2001 Jaguar XJ8, filled up with petrol and engine went from running fine to very lumpy immediately I started the car and (I think) before I moved off - I assume that a fuel problem would have taken a little longer to show up as 'good' fuel was still in the pipes but problem could simply be bad fuel.
DTC codes show as P0301, P0302, P0303, P0304, P1316 and P1111.
I think I can rule out plugs and coils as bank of 4 cylinders instantly affected. It may be a coincidence but there are only DTC codes 301 to 304 and not 305 to 308. The engine ran 5 miles getting home from the petrol station, I then cleared the codes and took for a fast run and same codes reappeared plus P0174 weak mixture. Car accelerates well to 70+ mph but slow running a bit jerky and tickover is lumpy.
Is there an electical component which controls cylinders 1 - 4 and a similar component for 5 - 8? If so, where is it located and can it be swopped with the module for the other 4 cylinders to try and move the fault?
All suggestions welcome.

 

Yes, possibly an Ignition control module (2). Each controls 4 cylinders.

If you're a 2001MY you should be in a different forum. This one is for 2004 (2003 UK) and newer.

 

problem identified as secondary cam belt tensioner broken

 

thanks - main agents say no sales for this item so probably not the cause

problem isentified as secondard cam belt tensioner broken

thanks for suggestion

 

You were very lucky !!!