tps evaluating for ii issues

[dave]

Max, Sportsterdoc, Ferret, and popgun, thank you all so much for all your help. Update: Rode the bike tonight on a nearly identical trip that I rode last night, only exiting the freeway about 3 miles earlier. Temperature was in the mid 50’s to low 60’s. Bike exhibited no unusual idle symptoms during start-up, and while at stop lights during the initial one mile ride to the freeway entrance. Reaching the first stoplight after exiting the freeway the idle dropped to about 900 RPM, and rose to approximately 1,000 RPM. While I don’t consider this terrible, it’s a far cry away from the perfect idle conditions I sometimes experience when the idle speed cleanly drops to 1,050 RPM, and remains rock steady. When I reached my destination and stopped about ½ mile from the freeway this exact same 900 – 1,000 RPM idle condition remained. I turned the engine off for approximately 1 ½ hours before restarting it to return home. The idle speed was about 1,050 RPM, and remained so at the only stop light on the way to the freeway entrance, about ½ mile away. I rode about 24 miles on the freeway, averaging 70 mph, and reached my exit where the idle speed immediately dropped to about 500 RPM when I pulled the clutch in; the engine would have stalled if I hadn’t twisted the throttle to keep it running. I proceeded to the first stoplight, approximately 300 yards away, where the engine immediately stalled. The engine restarted, but required careful twisting of the throttle to keep it running. I proceeded home and pulled in the driveway, and the idle dipped to about 700 RPM, and then slowly rose to about 1,050. I blipped the throttle a few times to see if the condition was repetitive, and it was, each and every time. I turned the engine off with the key and went into the house to get a flashlight. I restarted the bike about three minutes later, and it was idling normally (1,050 RPM), even after a few twists of the throttle. So I rode the bike around the neighborhood to try to get the low idle/stalling condition to return, but it didn’t. Instead, the idle would drop to about 900 RPM, and then work back up to about 1,000. This repeated 4 or 5 times over the course of approximately one mile. I pulled into my driveway and turned the engine off, using the key. Next, I unplugged the TPS, and restarted the engine. I got the flashing “check engine” indicator (8 flashes), and the idle seemed to be acting exactly the same as it was just previous to unplugging the TPS, except the throttle response was very poor (just like in the video Max posted). So I took the bike for a ride to see what would happen, and discovered the engine will not rev past 3,000 RPM with the TPS switch disconnected! There was no change to the way the bike was idling – it would drop to approximately 900 RPM, then increase to just about 1,000 RPM (far from a perfect condition). I rode it about 1 mile with the TPS disconnected, stopping to check the idle speed a few times, and there was no change. Try as I might, the engine will not rev past 3,000 RPM (I didn’t open the throttle 100 % though). It starts shutting off at about 2,800 RPM, and by 3,000 it acts like either the fuel is shut off, or the ignition shuts down. I returned home and reconnected the TPS switch and restarted the engine. Idle was now at about 1,050 RPM, even after a few twists of the throttle – so it actually got better after reconnecting the TPS (the normal throttle response immediately returned, and the ability to rev past 3,000 RPM also). So that’s the latest.