I have a 2001 FLHTCUI with the following mods: 1550 Big Bore stage 2 down load, SE203 cams, SE air bracket with K&N filter and SuperTrapp slip ons. New oil pump and tensioners along with new lifters.
The problem is while it is idleing it will sneeze / cough every few seconds through the AC. This happens without blipping the throttle. Once the engine is warmed up it is not as noticable. I have put a new TPS and stepper motor on with no luck. The idle also idles real slow from 2000 - 1000rpm once you blip the throttle. It doesn't drop to 1000rpm quickly after letting off the throttle until engine is fully hot. Never done this before. The dealer has replaced the intake gaskets, plugs and wires. Checked the setting on the TPS and got the idle to work alittle better by adjusting the TPS, but this made the cough / sneeze more noticable. Dealer has pretty much told me that I have 2 choices to choose from and that is either have a better idle response with more coughing or a slower idle response and less coughing. I told them I want it fixed. I am not going to choose between 2 different problems and pick the best one to live with.
From the items listed above that has been checked / changed out, is there any other ideas?? Has anyone had this type of issue and if so what fixed it? Dealer is waiting to put a new set of injectors and a fuel regulator on and after that if it doesn't fix it they have no other ideas.
Problem started after they put in the SE203 cams and the stage 2 flash in the ECM.
Thanks.

 

Interesting post, since today I almost dumped my 08 RK because it died on me pulling out of a parking spot...at idle. Well, I got home, I parked it and it wouldn't idle. It was coughing and then it would kill. So, I took out the PCIII and loaded a different map. I started it and idling seemed fine, but won't know until I get on the road for a test ride. DynoJet gave me some suggestions to help reduce decel popping, but I think I had the idle setting just too low.

 

Yo Electra1.....I think you should at least bench test or replace the IAC valve. IIRC when at idle and cold the IAC will control the RPM....keeping it running. if the valve is sticking it will cause the caughing your reporting. You could also check for codes...?
You said you have the stage II DL....but do you have any sort of fuel managment system on it? If your running a SERT I would suggest getting a dyno tune done by someone who knows what time it is. If you dont have a SERT or another type of fuel managment system....you should start thinking about getting one ASAP.

 

My '02 FLHTCUI was doing something similar. My bike has the same configuration as yours except I have the 204 cam and had SE slip-ons. It would have a few fits and sometimes die after a cold start almost causing me to drop it a few times. It would idle fine when it was warm but it still lacked power. i would occasionally get a historic code 25, which indicated the rear cylinder wasn't firing. This past week I put on a set of D&D Fatcats and it ran a lot worse. I had a ThunderMax at home but wanted to see how it ran after just changing the exhaust. I got it back home and put the ThunderMax w/Autotune on it. All I can say is "Wow"! It idles and runs better than it has in a very long time. I can actually feel the torque now. I am not an expert but it sounds like your bike has the same problem my did, a bad tune. IMHO the MOCO downloads just suck. They make your bike run too lean. I don't think you need a new exhaust but I highly recommend you get some kind of tuner. I went with the TMax w/Autotune because there isn't a good dyno tuner within a couple hundred miles of where I live. It is also easy to change if I make any future mods. Good luck.

 

Thanks guys for the quick responses. I do have a PCIII USB, but I took it off when checking to see if the problem went away without the PC. It didn't, but with the OEM stage 2 flash in the ECM I guess that wouldn't matter. The idleing issue when it comes to idleing down real slow I feel is part of the problem with the coughing. Any ideas about the idleing. The ICA was replaced with a new one just a month ago and no change. You can see it step down from 1500rpm at start up and step down to around 1000rpm within a few seconds from start. Would a bad engine temp sensor cause these issues? What about the air intake temp sensor? Thanks again for the imput!!
Electra1

 

(Bump)

 

The problem is incorrect TP sensor voltage. The TPS should be set at .275vdc. This adustment is tricky because you need to bak the throttle cable off completelty, then back off the hot idle screw. Tap the throttle plates slightly closed with a screwdriver and set. The variance is +/-.02 vdc. Then adjust the air bleeds in the top of the throttle body to 1.5 turn from lightly seated. After this reset hot and cold idle settings and put the stage 1 setting in the ecm. This should cure all issues.

 

Thanks for the response. Why would I put the stage 1 back in the ECM when I have a stage 2 set up? Are you saying the stage 1 will run better with the SE203 cams?
Thanks,
Electra1

 

(Bump)