Engine shut down, would not restart. Several corroded ground points and corroded terminals. Indicated bad crankshaft position sensor. Replaced with new one from NAPA. Started to have the same problem misfire & shutdown at 4500. Installed new Bosch Double platinum plugs. After installation, engine would not start, no ignition spark. Reinstalled the old CPS, fired right up. The NAPA CPS had a significantly higher resistance when measured with multimeter. Took it back to NAPA for analysis. Awaiting results. I also had several issues at the same time. The corrosion was the primary problem and the second problem was introduced by the faulty NAPA CPS.
I'll update this when I get an answer from NAPA.