This one is doing my head in and has the master technician stumped. What annoys me even more is tha tthe bike is just out of warranty. So much for fit for purpose.

Symptom:

The bike starts normally (cold). revs settle at 1350 - 1400RMP. Once the bike is warm the revs settle down to 1000RPM. After a period of time and more noticable when sitting in traffic the bike will start to idle at about 1350RPM. When I twist the throttle to move away the bike starts to choke and if I don't get the revs high enough it coughs and stalls. Once it stalls it takes a while to restart and when it does it runs rich and with a black exhaust. The problem repeats on a irregular basis and the time between failure is also not regular.

I did a diag and it displayed the following error P0108 - MAP Pressure Circuit High Input. 

The techs had the bike for two days. apparently the 'puter' indicated a CANBus error' however, according to the team these errors are not that reliable. They also apparently checked the engine temp sensor which checked out ok. Over the two days the bike didn't play up at all and no errors were recorded. Please don't think I am having a go at the tech team. They always look after me and are a great bunch of guys.

I picked the bike up and it behaved fine for 169Km (I almost had confidence in it again, almost) then revs up and stall. Took it for a follow-on ride a few hours later and it played up after 6Km.

Bike:

FXDF Dyna Fat Bob - 2012 - Stock with the exception of V&H Slip ons. 

I am stumped and have no idea what to do next apart from push it over a cliff.

 

 

Pain is the ass issue. Going through exactly the same problem at the moment with my 2014 superglide. May very well be the same thing. Does your bike have the gear as well as RPM function. I noticed the gear indicator displays the wrong gear as im pulling up at the lights when the revs get all messed up like you described. I am currently suspecting a busted sensor or an inadequate map on the ecu (I didn't get it dyno tuned) but im not too familiar with the bike yet as I'm still under warranty and dont want to fuck it up by wrenching on it myself. Gotta invest in a shop manual asap.. My problem may be different though as I have been hit by two cagers (in one fortnight) the bike is quite damaged at the moment. But its going into the repair shop next Thursday and ill bring up the issue with them. If I get a potential fix I'll definitely post it up for you. Good luck with it mate. Let me know how you go.

I feel you pain on this one berserker. The fact the Harley themselves have no idea is concerning. Computer says no.
Engine temp sensor, crank position sensor, ECM, MAP, puter says no.

Come on Harley sitting on the side of the road with a HD that won't work is great for the ride free image.

http://www.obd-codes.com/p0108
 

This may be  a completly diffrent cause but symtoms were the  same on  my 07 streetbob, when I had it a few years back ..the air cleaner mounting bolts one on either side of the Heads   , well one was stripped, I bought the bike second hand & discovered that it was coming loose , resulting in loss of, well not sure compression / vacuum whatever.. but it ran like you said increased revs then stalling & so on, in your case it may not be stripped but an "O" ring may not be seated or missing or loose ??? just a thought sometimes any crazy suggestion can help. Hope this does cheers

I got my bike back from repairs last Thursday. All they did was readjust the idle and my air cleaner box was replaced due to crash damage. 400kms since then with no problems with the idle. Seems to have been fixed. Hope this helps. The poster above is definitely onto something. Definitely worth checking out as well. Good luck and hope it gets sorted soon