All injectors make a slight ticking noise. I do not know of anything that
would cause one to be louder. I would suspect that a loud ticking was
somewhere in the valve train such as a sticky valve, broken spring, worn
camshaft lobe, etc..

Fluctuating idle is often caused by a vacuum leak, either a hose or gasket.
A major tuneup should include checking and correcting any problems external
to the engine but often just means replacing spark plugs and filters.
Don Young

hey thanx don i did routine tune up yesterday and found this idling problem
gradually rear its head from previous suspicion. i also found a vaccum hose
that had been melted from sitting on the manifold.  tune up involved: oil,
oil filter, spark plugs, wires, dist cap, rotor cap,coolant, fuel filter
and a good wipe down. i drove it to work this morning and had heck of a
time with the idling, it actually turned off on me at one point.  ran
great after 2nd gear @2500 rpm's though.  

Have you recently disconnected the battery?
If so, go to www.jaglovers.org and go through the iscv reset procedures.