2008 Ultra engine cutting out
Posting for a friend who will be on here shortly. He has a 2008 Ultra that has been running great until a recent road trip. Otw home from Sturgis he started experienceing the engine cuting out when he would hit a bump or a dip in the road. If he has the cruise control on, it will cut out the cruise and almost act like there is no fuel getting to the engine. Then if he gets on the throttle it kicks back in and drives fine till he hits another bump or dip in the road. If cruise is not and he has the throttle open and hits a bump or dip it will backfire. Only when going over bumps or a dip AND only with a rear passenger. He came home from the trip and rode all over with out his wife on the back and the issue didnt appear. I told him not to ride with the wife anymore but thats not always an option. We checked the wireing harness from the ECM back and cant find any obviouse damage. Any thoughts guys?

Since that original post: All suggestions looked at.. I have no codes thrown..ALL wiring harnesess and exposed wires pulled, twisted and manipulated. After speaking with a bike tech, friend of a friend, the injector wires and wiring in the fairing checked as well...nothing. ECM, Power Commander, twisted and manipulated...still nothing. Removed rear tire and checked harness to rear lights..all good and no signs of damage or rubbing from rear tire. Sat on bike, running and had 2 buddies pull up and down of the rear saddlebag rails to replicate rough roads...nothing again. I am lost on all counts as well as my buddies and those we have seeked advise from. Again, the ONLY consistency is having a rear passenger on the bike. This does not happen while riding solo.

After nearly a year of searching and guessing I took my bike to a dealer. They say they could not replicate the issues but found and cleared 2 codes but did not look any further? Never got a clear reason why. The codes are C1095- front brake light switch open and B1154- clutch switch shorted to ground. Since we had changed out the thumb switches from the black to chrome ones last summer, there is an indication we could have damaged something inside the right or left housing to cause this cruise control issue. Would it make sense to anyone to just go ahead and change the brake light switch and the clutch safety switch or can anyone verify those codes being related to cruise control issues? Or would it be a signal light module?

Many thanks again for your advice and feedback. I've gone grey from this so anything is appreciated.

 

engine cutting out is one thing

cruise turning off is another

do you have one or BOTH of these?

the cruise will turn off if the brake light switch thinks you have pulled the lever/pedal.
the past 30+ years manuals have detailed a shim must be used to prevent the front brake light switch from breaking if teh controls are being worked on.

that could certainly cause the cruise to disengage...but what about the motor quitting?

one of our members had a wiring to the sensors ( maybe the TMAP- can;t remember) being stressed as the motor bobs around on it's mounts and intermittent problems

also the fuel line disconnect seal has been a problem for some- pull and reinstall fuel line
also check plug wires for tight- plugs and wires should be oem spec

could also check fuel pressure and volume

Mike

 

If the engine rpm drops past a certain point the cruise will recognize that and disengage.
Given the symptoms you posted and that, when the problem happens, with or without the cruise I'd look to solve the engine issue and then explore the cruise if still needed.
For the engine, have you checked inside the fuel tank for something that shifts and could momentarily block fuel flow? I thought that sometimes the liner can fail and cause issues. I'd also check things like the crank sensor, IAC and tps and their associated connections and wiring. And not just look but remove the connectors and verify clean and well seated.

 

We had thought of fuel being an issue at one point but now with these 2 specific codes being thrown, it is sending us back to the lever housings and possible blunders we created earlier. As for the sensors, the dealer told me that "all" were tested, examined and cleaned.

 

Has there been a "flash tuner" installed on the bike. Unplug the rear fender tip light and ride it. Replace all bulbs, starting at the rear. Have battery cables been cleaned and tightened? A shorted dual filament can cancel c/control. A wet or corroded dual filament lamp socket can cancel CC. Start taking circuits out of the bike's system, front half, rear half and go from there.

 

Theres a PCIII on board but allegedly checked out fine. So, are you suggesting I remove the rear bulb to try and simulate the occurrence while I ride? Then replace and move on to another and so on and so on to see if its related to what you mentioned? One bub at a time?

 

If the 2 codes cleared by the dealer, have not re-appeared since the last engine cut out, I don't think the clutch switch short, or the front brake switch is your problem. The codes would have been thrown again.

 

Neither the clutch switch short nor the brake switch would cause the engine to stumble. Well, maybe the clutch switch short depending if it's bad enough to disrupt power to the ignition circuit but I think that unlikely.
Both faults can disengage the cruise though. But I still think the engine stumble and the cruise drop out are different, if related, problems.

 

So guys,,,Checked the bulbs as suggested and went for a ride with my wife on board. For the FIRST time in a year, the bike stuttered/chugged, while on the throttle and the cruise control NOT engaged. So i assume this goes back to being a fuel type issue ? Will change the fuel filter and checking the plugs....any other suggestions would be greatly appreciated.

 

If you haven't tried it yet - unplug the power commander and hook back to the ECM , i know you said it tested ok but its free and simple to try

Dave