XR8 series 3 issues

[Sox]

Ok gents, we have a problem.

The new machine, discussed here -
http://www.fordforums.com.au/showthr...8&page=1&pp=20
is having problems.

There are several issues, pinging, rough idle, and rough transition from no throttle to part throttle.
I suspect they are related and once the problem is found, all 3 issues will vanish.

I have so far replaced with new items -
Plugs
Leads
Fuel filter

No change.

I have swapped over with from my P250 -
O2 sensors
TPS
IAT
PCV

No change.

I have measured and determined they are ok -
Crankshaft sensor
Coil pack

The issues in detail are -
Detonation above 3000rpm under heavy WOT with 95 and 98 fuel.
Very rough idle when cold to the point of almost stalling. When hot it imprives, however is still not right.
When cruising, the transition from idle to part throttle (and vice versa) is not smooth.

The most interesting thing which happened was when I swapped the MAF, it was cured, temporarily.
Next day, the idle was still good, however it began to ping it's nuts off again.

The problems also followed the MAF, in that the P250 had issues. However the pinging didn't, so perhaps the pinging is something else.

I'm stumped at the moment. Any ideas?