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08 1200 problems

The IAC is a calibrated vacuum leak. When the twist grip is released or at Zero, the throttle body butter-fly is completely closed unlike a carburetor where you have a stop screw to leave the butter fly slightly open by just a crack. Think of this "crack" on a carburetor as a vacuum leak because that is almost what it really is. The IAC takes the place of this crack adjustment. It is a motor driven air bleed, or motor driven air leak, if you will.

The ECM has a "Set Target Idle value" in the software that can be changed using a laptop. The ECM measures the engine RPM from the crank sensor output and adjusts the IAC position to get the engine to its target idle RPM. There are limits of adjustment on the IAC. The IAC is a two phase stepper motor that does not have feedback control. By that I mean, at no time does (or can) the IAC tell the ECM where it's position actually is. When you boot the ECM during startup, the IAC homes the stepper to its "Zero" step position and then counts steps at that point.

The above is only applicable to Non-TBW engine idle control.
 
Completed Vacuum Leak test, Nothing found.

Also while doing vacuum leak test i rolled throttle a little and covered the IAC port with my finger, sucion continued off of idle speed.
 
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67hat34c said:
Completed Vacuum Leak test, Nothing found.
Click to expand...

Which method did you use.

Also I don't understand,, "port with my finger, sucion continued off of idle speed"

My mistake. I did not fully read entry point #1 of this thread about you cleaning your o2 sensors with brake clean and a wire brush. I just now saw that. You can't do that & they are probably ruined. When you get the new ones, install them and lets go from there.
Sorry I did not see that earlier.
 
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After cleaning it does not act any different. Brake cleaner was non clorinated type.

Re IAC. inside TB is is the IAC hole, strong vac at idle speed and above idle it seems to remain the same. My question earlier was if the IAC closes above idle speed. Apparently not.

Vacuum leak test was using propane torch. put tip up to all seams on the TB. Tested it holding gas in the TB and noted how engine changed as a base line.
 
That was a good vacuum test. (ok-check)

Does IAC close when above idle.? No. If it did, it would cause the idle to "hunt" like crazy when you released the throttle.

o2 sensors work by comparing outside o2 to combustion chamber %. There is a special membrane that allows them to sense outside o2 concentration as a reference. In most cases you will change the characteristics of the membrane when you wash the sensor. Never wash an o2 sensor.

I can feel it. Your getting close to fixing this bike!:p
 
It will get done, one way or the other. O2 sensors on my dime, everthing else has been Orlando HD. I knew cleaning them was risky but felt no further damage would be done. They very likely had a coating of something on the probe but due to the sheild with small slots, cant see it. Well I will cut one open after I get new ones.

Vacuum test with my torch was difficlut as I only have an instant on version and if you press button too far it lights up. Well at least i converted to Propane instead of MAP Gas which is way hotter when it lights off.
 
Your doing a Great job so far. While your waiting for the O2 sensors to arrive, I had some other questions. I want to get a clear understanding because this current thread is really an amendment to a previous post a while back and therefore can have some loose ends. I have 5 True/False questions.

1) At this time there are NO/NONE current or Historical codes in your ECM. Don't go by the check engine light. Manually check it.

2) Before this entire problem started, BOTH your tail pipe tips were BLACK and now BOTH of your tail pipe tips are Gray.

3) There is NO question that your MAP sensor was replaced and the new sensor was NOT removed because there was no change in performance at that time. The NEW map sensor is STILL installed in your bike even though replacing it had no improvement on your problem.

4) The bikes performance at WOT is "acceptable" and has NO obvious problems or issues. It does NOT exhibit "running out of fuel" "surging" or "nosing over on power" at the end of a 1/4 mile run in a tall gear.

5) Your compression in BOTH cylinders match and is above 180 PSI.



Things I would like to know but realize you can not supply answers.

1) What is your fuel pump pressure as measured by you.
2) Is the tune file you now have loaded to your ECM file name 176FM005 and has it been modified or changed.
 
1-Codes, Yes I keep clearing code for running too rich, either rear or front. I checked other used sporties on the lot and some others have the same code, think po152 but dont hold me to that.

2-Pipes were always black up until the fuel pump module was replaced. If it had changed any time before the march service I am sure I would have noticed it. I used it for about 300miles and pipe color did not change so I pulled plugs and found the white build up on the plug, then back to shop and rest is history. After Race tuner installed they did turn black again.

3- Not sure on MAP. I Know they changed it out in june but not sure if they changed it back. I am thinking it is running on the new one though.

4- No complaint on WOT runs

5-210 in both cylinders and both pump up evenly.


I did not measure Fuel pump pressure but I feel it is not issue as they did try to swap out the module a second time and actually reinstalled the one that was original. Its only problem was the low fuel light sender. No difference so the switched it back to the new unit. Tune file is not known but they have been doing the "supertune" as of the last visit.

I think that the only thing that has made any difference at all has been the last tune done in July. Runs a little different but still has the issues though seems different. There are times that it seems to run very well and if it runs that way for the Tech then I understand why he says seems to run good. The tech has never experienced the issues I have. They do believe me though as I have proven them wrong in the past and caught this shop in a couple of lies so they are doing what ever I ask. Nic is their best mechanic and from what I hear from other dealers he is the authority and "the best". Well even the "best" have stuff to learn and are wrong from time to time.

Now there is one nagging issue that came up after the fuel pump change, Riding in very heavy rain and it started to cut out, never died completely but it was cutting out pretty bad. Got home, washed and blew dry and it was fine. Now a couple of weeks ago I was on way home from work and tried to out run the rain and got caught, Very light rain but again started to cut out. I was thinking of barometric pressure change making the thing act up as it was not raining enought to do this.

Plug wire damage ruled out and not grounding on the chrome around the plugs. Put my hand under tank while riding and felt around coil and no shock.
 
The reason why other Sporsters on the lot have codes is probably due to them having piggy back fuel controllers on them. Your bike should be clean of codes since you are SEST mapped and no piggy is installed.

As far as rain issue and engine cutting out.
1) Try taking a garden hose and hitting the front of the engine where the crank sensor is mounted. See if you have any change with engine running.

2) Take a spray misting bottle of water and hand mist the coil/ wires and plugs while the engine is running. See if you can get the engine to miss. Hit plugs, wires and coil tower with hand pumping mist.

Install the NEW o2 sensors and see what happens. Codes should NOT appear.
Map sensor is a "loose end" since we don't know for sure if it is new.

Has the TPS been checked with a meter for flat spots in resistance? Especially in the 0 to 40% range area.
 
TPS has not been checked. I thought the same and considered just throwing on the part. Had another post about this where you idicated it did not need recalibration if replaced, seems to be plug and play.

TPS seems to be a simple resistor so I would suspect hooking ohm meter to it and rolling slowly to make sure it changes on constant curve, am I right?
 
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