For the last year and 1700 miles it's ran great. Yesterday I fire it up, let it warm then head out. I hadn't gone 600 feet and shut it off to talk with a neighbor. When I hit the key again it was all it could do to idle. It sounded like it was starving for fuel or air. The engine light was on and after many attempts I got it to run without dieing, but just barely. I kept the throttle steady and it was pulsing between idle and roughly 2500 rpms. But put it in gear and it would die. Got it running again and was able to limp about 10 feet in low to get me out of the road. Waited about a minute and tried again and it ran perfect like always. Drove it the rest of the night and never had a problem restarting. Today I went to the shop to fire it up and it made a plunk noise like it backfired in the muffler and was stuttering pretty bad. I never touched the throttle and it smoothed out on it's own. Drove it all over tonight and restarted it at least 40 times trying to see if it would do it again, but it fired up with no problems. Any ideas?