Still thinking bad fuel, I put some HEET brand fuel dryer in and ran it down to 1 bar. Filled up and added some Seafoam. Ran it some more. Fresh gas now but problem persists.
Also disconnected the new accessory fuse box I had installed. the relay trigger was driven from one of the hot wires leaving the factory fuse block. Don't think it was related, just wanted one less factor in this puzzle.
I had left one of the evap hoses disconnected.. fixed that. Explains the slight fuel smell which I was blaming on the DR.
narrowed down description of symptoms..
starts easy, but FI light on and stays on at idle, idle fairly smooth ~1200
giving it gas slowly, FI goes off around 2000 rpm
at PRECISELY 3500 rpm the bikes starts coughing/sputtering. 3500 every time. If I back off the throttle quickly sometimes it will even cut off. If I continue to roll on, once above 3600, business as usual. If you jump on the throttle from dead stop and run it on up to 5000 you'd barely even notice. Just can't go slowly though 3500 range, it'll start jerking.
I'm starting to wonder if it's an ignition issue. why would a fueling problem only really act up at a certain rpm. and I mean on the button, 3500. am I having an ECU problem?
Earlier I had thought about pulling the tank, dumping the (now fresh) gas and pulling out the pump for inspection. I'm starting to doubt that now.
Any other ideas? lets hear 'em. Thanks. Dan
Last edited by ddlewis; 02-06-2015 at 01:26 PM.