I would definitely have the ECM flashed. I cleaned my IAC, replace the TPS and adjusted the voltage to spec (it was a little low) and while all this helped, after riding a ways, coming to a stop the idle would still drop way down. After the flash, the problem was fixed. I've put 20k miles on the bike since the flash and still no problems. 65k miles and going strong.

 

They are just a spring and a washer sealed by an o-ring. They usually dont fail. What fails is the o-ring, or where they mount up is cracked, or some foreign object is preventind the washer from seating and doesn't build proper tension.

 

Alright, I found the problem. Once I opened the tank up and got the pump and filter assembly out, I noticed the regulator wasn't seated in the housing because of a bulging o-ring. It pushed down so much that it broke one of the two tabs that positions the regulator housing in place. The attached picture tells all.



I went to the dealership and got new everything - filter, hoses, regulator, and housing - just in case. Put it all back together and the ol' girl is running great. If she returns to dying after long rides when returning to idle, I'll take her in for the ECM update. As of now, she is running really well and sounds a hell of a lot better.

Gentlemen, I really appreciate all the help and the ideas to troubleshoot this. I can't say that enough.

Thank you,

Mast

 

So your high RPM idle was from too much fuel pressure. Appears from a failed plastic part. I think? Glad you found it.

 

Ripsaw,

Fortunately, I am not one of the guys with a high idle issue. It was a low idle problem. I've stumbled across several folks having a high idle issue with their '07's, but I was never one of them. My bike would just die when returning from higher RPM's. it got so bad that the bike couldn't even hold an idle. Obviously from the weak fuel pressure caused by the regulator and housing separation.

 

Glad to hear it got resolved.

 

Great thread.
Mast, what did it cost for all the parts you bought I think I might have the same problem, although I havent confirmed it yet.

My 07 road King police has a rough low idle, it idles about 950 rpms to 1100 at times, but is rough and shakes the heck out if the bike, way more than my 04 road king ever did.
Its definitely not the normal Harley idle its a lot worse.

I have 33k on it and bought it used a month ago so from reading all this I am going to look in the tank first and see if possibly that is my trouble as well.

I sure hope so, it would feel good to fix it and know I have all new parts in there again.
Great thread, lots of good info, ill post my findings as soon as it stops raining and I can get out there to have a good look.
Lump

 

My '07 has always had a "shaky" idle since new. When I test rode one in sturgis, they told me the twin cams did that and was smoother at highway speeds, which it is. My EVO was smooth at idle and shook more going down the road.

 

After starting this thread back in 2010 and watching it stay alive through the past three years I have yet another report to make. Last fall I had a revival of the high-idle issue I reported originally and it recurred several times until the weather turned cool when it stopped for several months. This spring it has returned and has become common lately, sometimes starting as a high idle followed by a low, stumbling idle that would nearly kill the engine. One symptom reported previously but not experienced with the latest issues was a rare and sporadic misfire at highway speeds.

I have been watching TPS voltage on my Power Vision display unit for some time and have noticed that at idle it has been jumping around rapidly between .15-.52v but smooths out and stabilizes as TP and TPS voltage increase. It should read around .50v at idle. Having seen these symptoms before I was sure the TPS was at fault so today I changed it again only 16k miles after the last in June 2011.

I took it for a test ride and noticed that TPS voltage at idle had stabilized between .51-.53v, a marked improvement over the old defective unit. I looked at it and noticed that at the 0% TP position (idle) that the center section that moves with the throttle shaft was looser than in other positions. I put an ohmmeter on it and noticed that if I moved the center section laterally--i.e., not linearly as it would move in normal operation--the ohmmeter would fluctuate, which it clearly should not, but if I moved the mechanism off the idle position it did not change.

My conclusion is that somehow the TPS mechanism is wearing at the idle position, probably due to engine shake. The '07 96" engine on the old frame produced more shake than in previous models and I'm wondering if this is the cause--excessive shake causing the TPS to wear prematurely. A friend with an '06 RG (stock 88" engine) has 47k and he has had no problems with the TPS, but his bike idles much smoother than mine. The '08 had the same frame and engine but had no TPS, so the '07 is the only year model with this combo (old frame, old engine-mount design, 96" engine, and TPS). I also wonder if maybe the throttle shaft may not be quite straight, causing the TPS mechanism to wear prematurely as it shakes at idle.

I think I'm going to have to resign myself to changing the TPS every two years or so, which I can handle. At $32 and taking only maybe 20 min. to install it just isn't a big deal. About 10 min. of that is to remove the AC hardware and another 10 min. to remove and re-install the inner bolt, which is difficult to access. For that I used a small Torx bit that normally fits inside a ź" socket, but for this job I slipped it inside a ź" ratcheting box-end wrench. I thought about going to Ace Hardware and buying an Allen bolt instead, which would be easier to install with a long ball-end Allen socket, but it just isn't that difficult with the stock Torx bolt.

 

Iclick. Thanks for the update. Last year I had the freeway stumble and it was the TPS at fault. I too believe that changing them every years is a good idea or keep one on hand.