If the plugs, wires, and coils have never been changed within the 90K miles I would have this done as a preventative maintenance step. Replacing the RCM, cam position sensor, and crank position sensor are also good items to replace. The RCM is probably the most problematic control identified on this forum. Once the marginal cold soldered connections on the RCM pc board are repaired and relays replaced the reliability of this control is dramatically improved.