Shortly after I bought my 86 coupe, a novice (didn't know he needed to be in reverse before shutting down) managed to jerk the key out of the ignition while the car was in 1st gear. I thought I noticed that the key behaved a little differently, but it still worked alright.
I recently had two new ignition keys made at a Chevy dealership. The new keys would not work in the ignition. They re-cut them using Chevy stock keys, including the resistors. I can get these new keys to work with some serious fiddling-- I have to reinsert the key into the switch 3-5 times before it will finally turn ON and start the car.
I don't know if the key story is related or not, but I have been having problems with the 4+3 transmission since the 1st gear jerk. The OD is very sporadic-- sometimes it drops into OD correctly, sometimes it doesn't. At those times I can fiddle with the ON/OFF switch on the gearshift (maybe 15-20 clicks, sometimes more, sometimes less) and usually get it to drop into OD. Usually, though, when I pull up to a STOP light/sign and put it into 1st to take off, it drops out of OD and doesn't drop back in automatically when I shift through the rest of the gears.
I have replaced the OD ON/OFF switch. That had no effect.
I have cleaned as many of the ground wire connections under the hood as I can find, and disconnected/reconnected most of the couplings in the wiring under the hood, trying to make sure I had clean connections. That had no effect.
This week I replaced the OD Relay under the hood. That had no effect.
I'm trying to eliminate external possibilities before seeking help with the transmission itself. I've been told by S-K that the 86 and newer 4+3s were pretty reliable (mine was a 1-owner with 39000 miles when I bought it).
Could the ignition/key problem be causing an electrical or sensing or relay problem that would make the OD balky?
Thanks for any advice.