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03 Ultra engine missing

More excellent insight, thanks.

I just replaced the wires from the throttle position sensor, no help.

The plugs were dry black, more like not firing as opposed to oil blow-by, also I don't have any smoke in the exhaust. I'll check again but the pipes seemed to be just dry black soot, not sure if excessive though.
 
coop85 said:
...the pipes seemed to be just dry black soot, not sure if excessive though.
Click to expand...
Hard to tell if dry. My Hookers have surfaces, just inside, that I keep clean (being chrome, facing out, and all). Sometimes I can read my pipes because of that. Otherwise, real hard to read, unless wet or oily. Club members raz me because I polish the inside of my pipes. Hey! It is what it is, eh?

Good luck. I really hate intermittents.

Rich P
 
Based on another suggestion I warmed up the bike then put in new plugs to see if the problem is immediate. It was, however I noticed on both the old plugs and the brand new ones after a very short ride the tips of the plugs are white. Also one symptom I failed to notice before is the bike will sometimes lose power before actually missing. I noticed (again sometimes) a drop of 4-600 rpm from 2,000 in neutral prior to an actual miss.
 
Power problems should manifest on both jugs. However, if a power problem, here are possibilities, that also might not throw codes:

Low battery
System relay contacts
Main circuit breaker
Related connector crimps and connections
Ignition switch
Handlebar kill switch

Specially, check the main positive line from the battery at the top of the starter and at the battery.

Enjoy,
Rich P
 
I replaced the main CB as it was physically cracked, loosened, cleaned and tightened the wire from the battery to the starter and have wiggled and pounded on the wires to the ignition switch and cutoff switch with no effect

I've been on the waiting list to get it to the dealer but still no openings until 2 Aug.
 
RibEye said:
Power problems should manifest on both jugs. However, if a power problem, here are possibilities, that also might not throw codes:

Low battery
System relay contacts

Enjoy,
Rich P
Click to expand...

Could you explain more about the system relay contacts? I'm guessing the EFI system relay that's under the right cover near the ECM?

Thanks,
Marcus
 
I don't have my schematic with me, but I do remember that the fuel pump is driven by one set of contacts in the system relay. I discovered this while looking at the crank position sensor (CKP) as possible source for my stuttering. If the ECM does not see pulses from the CKP for a certain period of time, it will open the system relay. There is another somponent or subsystem powered by a set of system relay contacts, but I don't remember which at the moment.

In any case, if you have corrosion on system relay contacts, or connector blades, you could have intermittence in fuel pump operation, resulting in low fuel pressure. It won't throw a code until the pump stops long enough to cause pretty much complete combustion failure in one or both jugs. This failure will be detected by the ion sensing associated with plugs and coil. She will really be running bad at this point.

Enjoy,
Rich P
 
I finally gave up after trying everything under the sun and took it to the dealer yesterday. They seem to have found a crack in the rear cylinder head. It's somewhere behind the spark plug hole. After looking at it myself there are rust colored deposits on the head in the area that is open from side to side. Spraying carb cleaner in there does cause the engine to speed up or choke. I'm looking at replacement options, but in the meantime does this signal any ideas for anyone?

Thanks for all the great inputs.
 
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