2003 FLHTPI, 16K miles, recent S&S Gear drive cams, PCIII, stock pipes, Ness Big Sucker as an open element air cleaner, Feuling cam plate/pump

Bike runs great, pulls like a freight train

Bike keeps coding for lack of combustion in the front jug, only happens at speeds above 62 MPH, and in 5th gear

Check light comes on, stays red, will go away on restart, with the stored code indication showing.

Replaced plugs and wires, still codes

when I load up the engine in lower gears I get no C.E.L.. The front plug is gapped .038, and shows no sign of fouling, gas, oil, or otherwise. I can bring the bike up over 5 grand in any of the lower gears, no light, kick it up into 5th, within 10 seconds it is coding


Now.... If anyone knows something I don't about this issue I am all ears.

I know HD used some ion detecting system to detect misfires, and it monitors voltages in the ignition system to do it.

I am planning on installing a Thundermax soon, just need to swap put the front pipe so I can get the front O2 sensor into the exhaust stream, but I don't want to change out the ECM without resolving the current issue...

All I can come up with is the coil has somehow gone slightly out of value somehow...

opinions?

 

P S I pulled the PCIII out and ran it on the stock ECM, still tossed the code, so I have eliminated that as a cause

 

bump to the top....

Beuller.... Beuller.... Beuller...

 

Spark plug wires tight?...last time they were replaced?

fuel injector connections good? Heat sensor good...good connection?

Sounds like the wind may be pushing something around.

 

I had the front cylinder code and my ECM was bad....but it was in every gear....limped home on one cylinder.

 

End of story:

slapped a new coil in it, no more code at any speed/gear/rpm