But all was well before you rebuilt the engine?

If you unplug the ISCV does teh 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 teh breakpoints ive used in teh map. However... this sounds a wierd one, but dont dont discount a faulty FPR spraying fuel into teh plenum via the compensation pipework.