i would check all the spark plug wires. check from the boots at the distributor all the way to the plugs. look for cuts, breaks or any way that the electricity could be arcing to a ground. an ingnition coil makes enough voltage that when jumping through the air to ground, it makes a loud clicking noise.

formerly 277000_yota
Old enough to know better, but still to damn arrogant to care...
]www.cardomain.com/ride/2614269
'90 'Yota 4X4 (10/31/05-09/10/08 R.I.P)
'98 'Yota t-100. 3.4, 5 sp. 4x4, 2 in. Toytec with BFG A/T 265/70R16s