So 2nd day of owning my new old 1991 RS with 350 swap, it is a high compression build as I was informed by the previous owner and tends to knock the starter back when cold.

I went to start it this evening and it started to crank but then the starter disengaged the flywheel and is stuck running. I had to hop out and disconnect the battery's ground cable.

I've worked on a number of starter issues in the past but never have I had one stuck running, I'm guessing it will be a relay (solenoid) stuck somewhere possibly fused due to load shock but has this issue came up with anyone else in the past?

Any advice on a possible fix if you have heard of this?

 

Usually when that happens the main power wire and the ignition terminal wires are making contact. If they aren't then it could be internal to the solenoid.

 

Could quite possibly be that the ignition and +12 supply where making contact. The ignition was loose enough to move by hand so I pulled it away from one side, and tapped on the solenoid while under there just incase. Back to operation.

Appreciate the comment on diagnostics, I sorta was overlooking that as a possibility for some reason hehe.