1996 Tour Glide Ultra classic, bike has a Magneti Marelli fuel injection system. Bike will rev up on its own at times, anywhere from 1500-3000 rpms. Hit the throttle and no response, will run at higher rpm's for about 20 seconds, In gear or out, hot or cold, I never know when its going to rev up. Anyone have any tips on repair, what the hell it could be ?!!

 

I had the same symptoms on my 97 RK. It was the heat sensor screwed into the cylinder head. There has been several revisions to the part when i was having issues with mine (98-2002) Make sure you get the latest part.

 

Thanks, I would have not started there but hope it works out. Much easier and cheaper than what I was thinking. Thanks again!

 

As mentioned 99% of the time for the EVO Magneti Marelli EFI it's the engine temp sensor causing irratic idle as well as reduced power from being too rich due to the ECM defaulting to rich-running when the temp sensor is bad.

Also, as mentioned, they've improved the reliability quite a bit over the years of revisions.

Bob

 

Thanks Bob, I never heard of the high rev-ing ( sometimes 3,000 rpm) issue which I'm dealing with sporadically. Always idles good and no low power issue, I hope this takes care of the problem.

 

I had the same issue on my 1998 FLTRI. I originally thought it was the ETS, but it ended up being the Idle Speed Control motor (IAC). Probably would not hurt to swap out the ETS first. I usually will not suggest playing substitution mechanic, but on a 21 year old bike it may be time for a new ETS. If it does not work then try the IAC.

 

Thank you for the advice, as soon as I pull it out of storage I'm going to start working on this issue. As I said, didn't know where to start so all help is greatly appreciated. Thanks again

 

Unplug the fast idle stepper motor and see if it goes away, don't see the ETS having the ability to over ride a fast idle speed to 3000 plus a stepper motor won't lose throttle response.

Saying it won't rev up when acting up is heading towards loosing fuel pressure going lean or a throttle position sensor going outside it's range. There is a video on checking and setting a TPS and a pipe plug on the bottom of the fuel line entering the fuel tank for a fuel pressure check

 

ETS tells the ECM if the engine is cold (lots of fuel and high idle) and changes the fueling as warmup occurs.
If the ETS sensor starts going bad most of the time idle fluctuates from ok to high for a while, until the engine either gets hotter or cooler which, in turn, can send normal reading back to the ECM, which in turn, lowers idle speed to hot idle speed.
This is why folks will "chase the sensor" trying to get proper idle behavior by readjusting idle screws, both hot and cold.
Change the ETS (it's way past due IME) then se what's up.
Bob

 

Did you ever determine what was causing this problem? I am having the same issue, reset the tps and was good for a day and now right back to the same thing.