Originally Posted by Stu @ M Developments

But all was well before you rebuilt the engine?

If you unplug the ISCV does the engine speed stay in the 900s? If not, fix that first as the engine needs to stay above 800 for the loop to work correctly due to the breakpoints ive used in the map. However... this sounds a wierd one, but dont dont discount a faulty FPR spraying fuel into the plenum via the compensation pipework.