I have developed a frustrating problem recently. Every once in awhile, always at a stop, the engine will act like it is dying, as if idle is set too low (my bike is an '02 EFI). When it does this, I have to keep a little bit of throttle on it to keep the engine from completely dying. It doesnt do this all the time. It first started earlier this year when I brought the bike out after winter. I thought maybe the gas had gone bad. Havent had a problem until just today. Seems like the bike, or idle, "resets" itself if I turn off the bike and start it again. If not, it will keep idling extremely low at stop.. to the point that the engine dies. Again, it doesnt do this all the time, just once in awhile. Any ideas?

Bike Specs:
2002 Fatboy EFI
PCIII
Stock ECM
Arlen Ness Big Sucker

 

Was there a solution to this? I have the same symptoms just recently (like today) and will try changing plugs. I heard on another forum that it might be the temp sensor going bad. I may download another or modify my fuel map to see what that will do??? lmk if you find something otherwise. Thanks!

01 EFI softail
SE203 cams
pcIIIr
Stage 1 flash
Big Sucker A/C

 

Speed sensor will cause low or no idle. My speedo would drop to 0 as problem got worse. Also noticed 6th gear would flicker on and off when engine revved with clucth in and not be in 6th gear. Replaced speed sensor, tightened pin fits at sensor connector, speedo, and ecm. No issues since.

 

The efi gasket body may be cracked, making the readings incorrect. take a look.

 

I think if you just have an idle problem I would look at the idle air control (IAC), on the older ones they did have issues with them sticking, just a thought. If you have a speedo issue or signals that dont cancel then I would lean towards a speed sensor like has been said above

 

my 07 has done this 4-5 times between 5-10k miles, usually just turn key off and restart. tuner said he couldn't find anything at 10k checkup and only done it during the first Yr.
Last yr dont think it did it once...

 

My 07 has about 14,000 on it and had also done this randomly about 3-4 times in the past 5,000 miles.

 

Great thread. My bike is at the dealer right now with the same issues.
No idle and speedo goes out, turn signals won't cancel.
07 Train with just under 20,000 miles.

I'll post up again when I hear back from them.

S/F
Freefall

 

To the original post, I'd try standard spring maintenance items and see if those make a difference. Change plugs, oil, Run it enough to get old gas out and get another tank or two of high test new stuff through there. You could also use an additive (friendly to HD's) that will help get rid of any gunk in the engine that may have resulted from bad gas.

Start with the standard maintenance stuff before looking at sensors, gaskets, the proverbial alternator failure, etc. Since you say you didn't experience any problems before storage it would seem the obvious cause would be something related to storage and the most likely culprit would be gas gunk fouling the plugs and fuel system and/or water/moisture in the gas.

Once you go through all that you will either have it fixed or have had all simple stuff ruled out and then you can start looking at more complex and expensive repairs. It would suck to replace gaskets and sensors only to find out the money and effort expended was for nothing when the real problem was dirty plugs with a big gap.

 

My bike is still in the shop.
I hope to have an update in the next few days.
Been raining everyday anyway so I'm in no hurry.

S/F
Freefall