MPI Ignition Timing

[Zinger]

I need some help with the timing on a 2000 350 mpi , does any thing need to be disconnected or shorted while making any adjustments. Thanks Jeff

[Rootsy]

yes there is if it has a Thunderbolt V ignition system... the purple (or is it purple w/ white tracer.. sorry i forget) lead with a black rubber plug in the end needs to be grounded when setting initial timing...