First of all, just today I realized I could pull my key right out of the ignition with the engine running. It's always been very sloppy, but I didn't realize it was this bad.

Then, I realized that I could kill the engine by bringing the cylinder back a notch, then restart the engine all without the key not even in the cylinder!

My car is a 91 so it's supposed to have VATS.

So my questions are:

Why can I start the engine without the key, has VATS been bypassed? How to check/fix this?

What do I need to replace to have a nice and tight ignition tumbler and retain VATS once it's functioning properly? I see lock cylinders for sale....will I have to have a new key cut to match the new cylinder with a resistor that matches that which is already on my car?

 

They will do that sometimes, if the cuts are "all downhill" on the key. They wear and the "pins"( they are more like wafers on the side bar cylinder) stick. I had a caddy that was like that. As for the VATS I don't know allot about them. ( just got one parts car with it) I would assume that it is only active when trying to start and you are fooling the car, it "thinks" it is still running with out pulling the key back to lock. Maybe someone with more VATS exp will chime in. Dad was a locksmith-can you tell?

I think you are correct but they both are prob worn. How does your key look is the nickel plating all worn off and the cuts too?