electical problem?

my 1991 jimmy has a problem. The distributor, distributor cap, rotor, spark plug cables, coil have all been changed more than once and the problem continues. It has been set to its correct timing also. When it is on, at times, you can hear this tick in or near the distributor cap and the jimmy chokes. The mechanic said it was the spark plug cables but i have changed them 4 times. Can this be a problem of too much current? Any advice on whats wrong?

A tick?

yea u can hear tick tick happens fast and sometimes its in groups of 2 or 3. tick tick tick or tick tick

Have you had the truck scanned for trouble codes?