Ok, redline gurus. I have an '06 RL. Stock with 150k. Has had some hiccups with the ecm, but nothing major. Left work to day, got 1 1/2 miles away and revs stuck at 4-5k with foot off the accelerator. Shut it off 2-3 times, but still did the same. Got off the road and disconnected the battery. After that, it will turn over and start up, but shuts off immediately. Tried to disconnect battery again and grounded out the cables together, but no change. Seems to be getting fuel. I'm at a loss. Thanks in advance.