New to the forum. Look forward to all the reading available. 😀
I have a 2010 FLHTCU that just had the original motor removed and a S&S 124 installed. Everything good except one pesky electrical issue. Was having a issue that felt like it had a miss between 2800 to 3200 rpm. Took back to mechanic and he thought there was an issue in the tune.

Took a long motorcycle trip after getting the mileage on the motor needed for break in....still had issue. Took to a recommended mechanic and he spent a day trying to diagnose. Here is what was done/tried.

Took reading at TGS and throttle body sensor..readings didn't match up with same numbers. (Cant remember numbers but one read like 7 and the other in the 20s but numbers should be same)
Tried a new TGS hooked up behind fairing and readings still didn't match up (Stated TGS isn't issue)
installed new Throttle Body, rewired from Throttle Body to harness in case wires got damaged....same issue.(Throttle body not the issue)
Tried a different ECM....same issue. (ECM fine)

No codes. Cruise button light was intermittent working and now not lighting up. Cruise works just fine. (Wasnt sure if this could affect the issue so figured would list it)

Mechanic that looked at it when I was on trip mentioned maybe a pinched/broken wire between fairing and ecm or Throttle body.

Have appt at Harley in 2 weeks to hook up breakout box and see if they can diagnose...not sure if that will even help me locate issue.

Any suggestions of what wires it could be or where to start looking? Anyone seen this issue?

 

Who tuned it...?

What did the tuner say about the TGS and throttle body sensor readings not matching up?

What if anything did the tuner check, change in the tune?

 

the mechanic who installed the engine also did the tuning of it, multiple times after motor to get it dialed in. The mechanic that checked it while i was on my trip just said tge reading of the TGS and throttle body were not aligning up with numbers. I guess the numbers should be the same at both points....so it's like the two aren't communicating correctly. The numbers do align occasionally but should align all the time. No tune changed while on trip, he didn't want to do until electrical issue figured out. His diagnosis was there was a wire issue from fairing back. Eliminated wire issue in handlebar since he was having same issue when that was bypassed.

 

Bypassed.
Clarification.... eliminated wire issue in handlebar... not eliminated wires.

 

Well, if the issue is in fact a bad wire, the easiest way to chase it down will be with the the breakout box....

Or else a lot of time spent with a schematic and a multi-meter..

 

Dose it run well everywhere else in the rpm scale..??? why do you say its an electrical problem ...what you may be FEELING is a bad spot in the tune ...
a lean or rich condition will also FEEL like a miss ...detonation as you are rolling in the throttle will FEEL like a miss ...
if everything else is work/running ok...we would look at the tune/map ..

Good luck ...

 

I have the schematics/manual. I have 2 weeks until appt. so figured I had time to at least check. Just need some guidance on how to test and what to test. I'm guessing wires between twist grip sensor and throttle position sensor.... and maybe ecm?

 

on my trip.... one stretch I got 147 miles on a tank of gas. Mechanic said front cylinder running rich and rear cylinder running lean....but the reading between twist grip sensor and throttle position sensor were not matching up. Said the numbers should be the same. Would not do any tuning until that was corrected as it wouldn't do any good. I can throttle thru it. At times I go to throttle and nothing then there is a pop, like a backfire, then it surges.....I'm guessing that's the tuning rich issue. Oh and at idle when warm, idle slows below 1000 sounding like it's going to die then back up.

 

I posted this response on another thread and reposting it here:

​​​​​​Had a 2012 Street Glide in my shop. Bike was idling very bad. Performed several tests on the codes that were stored and everything pointed to bad ECM. So I replace the ECM and its still running bad. I'm scratching my head and do the tests two more times and still the same outcome. Walked away and came back, and decided to check everything again and discover the issue: Bad connector. When I did the test on the TMAP sensor all was good. It wasn't until I plugged it back in and positioned it back on the throttle body that I discovered the one wire in the connector was loosing connection once the wires were bent back 90 degrees. Replaced connector and TMAP sensor, $40 and all was good after that.

My point is check the wires and connectors.

Ride safe!

 

@10FLHTCU

Got to Facebook and join Harley PDF Manual Trade and Share. Click on files and search 2010. Download the Touring Electrical Diagnostic Manual and read about TGS TCA in section 6.

Section 2 has a list of DTC's then shows you which page to go to to trouble shoot the codes. I'm surprised you don't have codes .