What can cause ignition timing to fluctuate?

[matt b]

The ignition timing on my CA18DET is all over the place at the moment. I have tried 2 different computers and 2 different crank angle sensors (condition unknown on both cas) with no improvement.
What can cause ignition timing to vary wildly?
Thanks Matt b

[BigMuz]

Interference to the wires between the cas and the ecu.

Bad connection to ecu or cas

[tandy ass]

Faulty knock sensor. Very common above about 1500rpm

[jbonevia]

Chewed out key on the end of the exhaust cam?

[matt b]

Hi guys
I have connected and reconnected the cas and ecu several times so I don't think it could be a connection issue.
Interference could be a goer but why would it happen all of a sudden?
Faulty knock sensor is also a definite possibilty. I have a couple of spares but unfortunately I don't have a deep enough socket to change it at home. Any ideas on which tool shops carry deep sockets?
The tang on the end of the exhaust cam is fine. I've spent a fair bit of time looking at the bastard over the past 2 days!
Thanks for the suggestions fellas. Keep the coming.
Matt b

[tim510]

what size socket do u need datto sam?

ive got a range of long ones

[matt b]

Hey Tim
How'd you shape up after Saturday?
Thanks for the offer but I may as well buy one as it's bound to be a problem at some stage. Where did you get them from?
Matt

[gmh265]

why dont you just try plugging in another knock sensor and leave it off the engine to see if thats it?