Hi Keith.

I have one with the same problem, same year and same engine code (1Z)

No fault codes stored, fuel filter replaced, high pressure pump replaced with a re-manufactured one and injectors were reconditioned.(or so i'm told?)and basic setting performed etc....

Idle hunts from turn of the key and it 'hiccups' at low revs but no loss of power and drives through it without problem. On the odd occasion the idle is perfect but soon goes back to a light surging (if that makes sense?)

Can you offer me your expert advice?

The car owner clearly loves this car as they have already exceeded the value of the car, but they want it fixed (I didn't do the pump and injectors by the way)

Thanks in advance Keith

Andy