I just bought an 85 rx7 gs, started working on it and noticed that i was missing a fuse so i put the missing fuse in but now when i turn the ignition key off the engine will keep running indeff, when i remove the fuse the engine shuts down just fine, i disconected the alternator and now the car shuts off whit the ignition key without any issue, and info on what might be causing this problem. Thanks for any replies.

 

Where was the fuse located? Does your car have any add ons that could be messing with the ignition switch like an alarm or auto start sytem? Either one is usually hidden behind the dash but you'd be able to find a small antenna inside the cabin somewhere

 

your ignition could possibly be worn. with the new car i got, i had to replace it cuz there was a dead spot between 2nd position and 3rd. the dead spot caused it to die after cranking it. with my 84, sometimes i'll pull out the key and the car will be off but when i open the door, the buzzer will still sound saying that my key is still in the ignition. don't quote me on it, but i would at least check it out.