Took my 2005 FLHTC Trike out yesterday as it had warmed up to 60 degrees and I hadn't ridden in some time. Made it approximate 25 miles and noticed a hiccup, which got worse until the bike ran on only one cylinder - the rear jug. Oil temp fine. Babied the bike home and went out today to have look. Plugs look fine, wires to the injectors look fine, plug wires look good but I know that doesn't mean much.
Only coincidence is I had a shop install a PC5 module and download a richer setting based on the tuner's experience with other similar bikes. Did run better (and cooler) upon collection, but it's been too cold here to really take it for a run..... until yesterday when all this happened.
Stock 88" TC with S&S cams, lifters, oil pump plus a SE air cleaner and mufflers.
Check engine light did come on while driving home but is not present now. I did take it out for a short 10 mile ride today and had no problems.
Thoughts on where to start? The guy that put the PC5 and did the tune is out of town right now. A local shop says the PC5 could be at fault, but probably not.
Thanks

 

if the check engine lite came on then there's a code stored

 

 

definitely check for a stored code. once you find that we an have some better info to help direct you. it probably would not to hurt to do a quickie compression test just to rule out anything mechanical before we get too deep.
m

 

Head Gasket ?

 

 

Thanks. That is good advice. Got to go far enough to get it hot, but not too far as the trike on one cylinder is not fun to ride.
I don't think it was the fuel as the tanks was only a couple of weeks old.
Right now out of town but will download ECM codes when I get home and advise this forum with findings.

 

Finally ran the codes.... and there were non stored. I know the CEL was on when the problem occurred, however it is not on now. Probably will need to ride it again and see what happens. 16 degrees this AM so it may be a while.
Is it probable that the recent installation of the PC5 and tuning could have caused this problem? Happened within 40 miles of installation. The tuner says "no". I have not located any loose wires, however it is coincidental.
The rear plug looked great. The front was a little carbon fouled (that was the cylinder that quit). Would you recommend replacement as a possible fix?
Also, should the oil be changed due to fuel contamination? Just thoughts.

 

what brand and number plugs are you running? other than non stock HD plugs sometimes cause weird cels.
m

 

Disconnect the PC5 and reconnect the main harness back to the ECM, if you continue to see the issue it is not the PC5 if you lose the issue then PC5 is most likely culprit.