So I'm out driving my "project" 240 around (the one that failed emissions testing) trying to run it out of 6-month-old gas (too lazy to drain the tank, and don't really have anywhere to dispose of 10 gallons of gas anyway). Car's running like a champ, and then I pull into the driveway and put it into park, and the starter engages! The engine's still running! I put it into reverse, and the starter disengages. Back to park, and the starter engages again! This time, I turn the key to 0, and the starter disengages. With the engine off, I turn the key back to II and the starter stays off (as expected), then turn the key to III, the car starts, back to II and the starter keeps running. Very strange, and it wasn't doing this before today.

I was patching wires on the engine wire harness yesterday, so the first thing I suspected is that I missed one, or accidently left some bare wire exposed. I did the patch job with the harness on the car, so today I took the entire harness out of the car to get a better look at it. It's in good shape (after patching) and I didn't miss anything -- so this is definitely not my problem. The yellow/blue wire going from the starter motor to the 8-wire gray clip at the firewall inside to the automatic transmission P/R/N switch is OK and is definitely not shorted out. So my guess is maybe a bad P/R/N switch or a bad key switch, or maybe a bad wire in between them? It was getting dark so I gave up for the night...

I'd love to hear any ideas about this problem. I'd also like to hear a description of the starting circuit, since I haven't yet figured it out. Thanks!