Join Date: Jan 2010
Location: Pensacola, FL, USA
Re: Still Misfiring: Suggestions Please?
You might try checking the oil pressure. low oil pressure when warm could cause inadequate tensioner pressure and a loose timing chain and erratic timing. Just throwing it out there because it sounds like you've checked everything else you can.
A quick and dirty way to check is to add STP or Gear lube to your oil, and raise the viscosity. If it improves things, you have a clue. If it doesn't, you do an oil change.
The only other thing that comes to mind is the ECU or a sensor that affects the hot running map. Temp sensor, O2 sensor etc.
Is something like the Air Box Temp sensor disconnected and the brown wire cut at the same time a possible problem on your bike? Yours is a 99 so you don't have a brown wire but someone may have 'upgraded' it to a later ECU and it may think the wire is cut....
Best of luck and here's hoping you figure it out.
53 MPG and life just keeps getting better
2001 Triumph Sprint ST [sold]
2000 K1200LT 'Nimitz'
Last edited by Centaurious; Sep 18th, 2013 at 11:09 pm.