Erratic tickover

[SM25T]

I would be looking at the throttle pedal pivot, and lubricating it 

[aerobod - near CYYC]

If blipping the throttle when the idle is higher than it should be causes it to return to normal, it is highly likely that the throttle is not returning to the stop position. Other than lubrication as suggested above, a fraying or jamming cable at the pedal end (precursor to the cable snapping), too much tension on the throttle body end (needs to be adjusted for a bit of slack), weak return spring, over tightened air filter (causes throttle blade to jam slightly open) or loose throttle blade are all things to check.

While the idle is elevated, take off the bonnet and press the throttle linkage against the idle stop, if that fixes the issue, then the above checks should be done to identify what is preventing the throttle blade from closing to the idle position. If the idle is still elevated with the throttle against the stop, I would check for air leaks in the intake system, ensuring all nuts and bolts for the manifold and throttle body are tight and any vacuum lines or blanking plugs to the manifold are tight and puncture free.

[AlanO]

Think you've sorted me out thanks James (and others).  Went over everything you mentioned and found the most likely cause was that the throttle pedal stop wasnt adjusted allowing the throttle blade to open too far and jamming/sticking.  Well I think it's sorted! Since adjusting the stop and greasing the cable etc everything seems hunky-dory!! Cheers!

[aerobod - near CYYC]

Glad that things are working well now, Alan.