I had the same sled. Both responses are definitely possibilities. The throttle body adapter plate was prone to failure from the factory the replacement is a better design. Look it over good a crack can be hard to see especially while it's still on the sled. I would suggest taking it off and looking it over good. If you do find it's bad you probably should get a look down in your jugs at the pistons and cylinder walls. Mine acted about the same right before it locked up. Does it die when you engage reverse. That's a warning sign of bad things to come.
