This whole issue seems to have something to do wit the tune I had done on my bike with the stock ecm in it. A couple weeks ago I reinstalled my thundermax with auto tune and downloaded the closest map recommended by Zippers. Bike ran well right off the bat. Runs even better now after a few tanks of fuel through it. (600 miles or so) Haven't had any problems with low idle or stalling even on long trips in hot weather. Time will tell I guess. Hell maybe it isn't the tune but something with the stock ecm. Tuner said if I had any problems to bring it back to him and he would put it back on the dyno which I'll probably end up doing. I got to say that I'm pretty impressed with how it runs with the T-Max and I may just stick with using it. Later on...... Mike

 

2006 ultra classic .... has zippers/thunder max kit on it. Ran well for a couple years. No issues. Now idle is erratic and most of the time hangs around 2000 rpm. It also exibits the "spitting" from the idle pintle. Im thinking I may have the IAC problem. The pintle actually does not move at all. I have the air cleaner off so I can see the pintle and when bike is cycled the pintle does not move at all ......

need that test light to check for sure i think though. any other ways to check to see if its the IAC motor problem or something else?

 

rh8234, I appreciate the detail you provided when describing the IAC function and symptoms. I've been having similar problems with my Roadking and trying to determine if it could be the IAC or CPS. I too had a bike that was running like a charm for some time. No hesitation on throttle, even if I started out a little cold. No choke like bog where you think it may shut off, when taking off from a start. I mention these because I've been there before and then I converted my 2000 MM EFI to closed SSCycle with VFI and all was good with the world.

Anyway, just recently, I started having idling problems. I took others advice and did an enema on the IAC, which cleared up the big idling problems. What I have left is this. Now starts and holds great Idle. I can ride a while and most part it does great, the longer and especially harder I run it, at some point, when I stop, my Idle is going to run up from 950 (where I keep it) to 1200, but I know its going to happen before I stop because I start getting popping when riding and during deceleration. Note that I have not had a backfire or popping on deceleration problem since I left MM and moved to VFI and got it tuned right.

The kicker you mentioned was the resetting and operating properly again after you recycle power. That's exactly what happens. It will continue the high idle and popping until I shut off, and can immediately power and startup and all's normal again as if nothing ever happened. As you said, the CPS could still be a suspect, but I'll replace my IAC first. Thanks again!! I can't offer much technically, but as it does for me, I hope my detailed description of symptoms will help some other poor sole diagnose their problem.

BTW! A note of those to you that may have an adaptive EFI such as Zippers THundermax or SSCycle VFI. I learned from mistake, but if you make any changes like cleaning your IAC real good after its been running like crap, whatever adaptive changes you've got collected will probably not mix good with the change. You may start off okay, but performance will get progressively worse. YOu need to remove the power from the battery and let the TM or VFI clear the adaptations so it begins again with your adjustment you just made. I've had it happen twice on me before it stuck. The last time was with just cleaning the IAC. Happy Trails!