So, to make a long story short, I've been trying to figure out some idling/stuttering issues on my bike.

After ruling out electrical, tuning, fuel, and most others, I decided to take apart the intake. Took off the air cleaner/backing plates. Removed the IAC and gave it a good cleaning. It was pretty gunky. While I was there, I figured I'd remove the TPS. Not much to it.
So I re-assembled everything, started the bike, and now it idles at about 1500 rpm.
Also gettin a TPS open/low efi error.

I've been futzing with it all night. Wires look ok (I don't have a meter), but why the code all of a sudden? Manual says TPS does not need to be adjusted after install. Maybe it was going bad in the first place?

Any suggestions?

 

What did you use to clean the IAC with?

 

I don't speak a lot of Harley, but SAE descriptions of codes is universal. Open/Low is an open circuit. Sensor is open, connection to sensor is poor, or a wire is open/broken.
ECM will go to default idle speed when the position sensor is not in place. Did you cram a bunch of grease in the connector when you put it back on? Did you pull a pin slightly from the connector when you removed it to clean it?

 

I used CRC Throttle body and air intake cleaner to clean the IAC and around.

didn't use any grease or anything. Pulled the sensors out, rubbed them down and re-installed.

I've checked the wires, at least at the connections, and the connectors. Cleaned those, reconnected, etc.

I do have a simple voltage meter that lights up when touching the connector, so at least it's getting power....

 

Is there a diagnostic procedure in the service manual for the TPS? If so, follow it.

I'm guessing it's just a variable resistor that has two or three check positions with given resistance values for each.

Go buy a proper multi-meter. They're cheap and invaluable for this type of trouble shooting.

Another posibility is low/no voltage at the sensor supply pin (or open ground). Again...meter and service manauls to the rescue.

 

No diagnostic in the service manual, basically just removal and installation. It refers you to the Harley Electronic manual....of course...

Good idea. Gonna at least grab a multimeter and see what I can see, or not see...

 

Just an update here, in the event anyone else runs into something like this.

I was unable to find any broken wires, currents were all good. Got in a new TP sensor and popped it on. No codes, Idling and running fine. I guess these things fail sometimes. $40 fairly cheap fix.

 

Sweet. Thanks for the update.