I have a 1999 Ultra Classic with the M&M fuel injection system, I recently replaced the throttle position sensor and set it using a multimeter. well now when I start it up it idles in the 950-1050 range that the service manual says but after idling there for 10 seconds or so the idle jumps up to 4000 rpm. I figured it hadn't been started for a while and it was cold and just needed to warm up, so I let it run for 5 to 10 minutes and it was still at 4000 rpm. I sprayed some starting fluid around the intake manifold and the idle didn't change. im not sure what else to look at figured this would be my last option before taking it somewhere to get looked at.

 

You let it run at 4000 in neutral rpm for 5 to 10 minutes??

That ain't good.

 

I was also wondering why you would do that. It probably didn’t hurt anything but why let it go that long?

 

You replaced the TPS, now it runs away, start there. I worked on alcohol dragsters and funny cars for years. Between rounds we only change one performance item at a time. That way you know if it had good or bad results. If you change two or three things at a time you don't know which one has the negative results.

 

If you haven't seen this, it's a good place to start...