Part Throttle Hesitation/Surge

[FJR-TX]

I've got a 03 that just turned 28k, I bought it back in the spring with 21k and everything has been fine for the most part, except the heat on the legs which really sucks living in texas.

My problem that has just recently surfaced is some part throttle hesitation/surging. I only notice it at low speeds around town 30mph. The throttle is barely open at those speeds and it seems like the slightly changed in throttle makes it surge or when i close it, it feels like the butterflys on the FI are closing almost instantly. then sometimes when trying to maintain speed, it starts jerking back and forth like 16 year old learning to drive a standard. I read the sticky about the TPS haven't had a chance to call Yamaha and see if it has already been replaced. I also read that the FJR came from the factory too lean, but the problem just started a couple hundred miles ago, and I figured if it was that I would have noticed it from the get go.

When at full throttle or I have the throttle opened up to accelerate I don't really notice, it's just the low speeds trying to maintain 30 or so is not too fun and in the rain down right scary.

Please help, my FJR is my only means of transportation and I need to figure this out fairly soon so it doesn't leave me stranded and with out a way to get to work.

Thanks ahead of time.

 

[ionbeam]

Call your dealer and give the service guy your VIN and he can look up the TPS info, quick 'n easy. If the problem is the TPS, it isn't going to suddenly and outright fail leaving you stranded. Outside of the aggravation of the surging you can continue to ride it while waiting for a replacement TPS to come in. If you are feeling adventurous you can do a quick test using the diAG function of the ECU and read the TPS yourself. This isn't a totally definitive test but it does often sniff out a bad TPS. I've got a procedure for testing the TPS in this Forum, I can help you find it if you are interested. The test takes <5 minutes.

Then there is the always famous, "Did you get a tank of bad gas?"

And, nearly as famous, "Run some Sea Foam or Techron in your next tank of gas and see if it clears up the injectors."

If the surging is happening in one narrow rpm band, regardless of gear then it strongly points to the TPS.

 

[RadioHowie]

^^^^^^^^^^^^^^^^^^^

Pay VERY good attention to ANYTHING this guy says!!!

 

[03HiYoSilver]

TX,

Check your Main Connector here:

https://www.fjrforum.com/forum//index.php?s...st&p=268059

This has solve a MANY of these types of problems.

 

[worldbound4now]

Where in TX are you located? You may be near a forum member who could help you out. Lean surge can be an issue, but your case seems pretty extreme. I personally notice rougher low RPM issues if I'm needing to do a throttle body synch. If you're in the DFW area, PM me and I could possibly do this for you if our schedules mesh up. Also follow ionbeam's recommendation of having the VIN run to see if you are under the TPS recall.

My 2 cents are exactly worth that... 2 cents,

worldbound4now

 

[harpo]

I had the same problem, Mine started after ridding it for a while. It was ok riding at speed but when I slowed down or was riding slow ,it bucked and jurked. I had the throttle bodys synchronized and that made a big differance. Yours sounds like mine, it only has twenty seven thousand miles on it and I bought it in April with Twenty four thousand and some change and I have no idea who owned it before me but it is a blast to ride and hard to keep slowed down.

 

[FJRBluesman]

^^^^^^^^^^^^^^^^^^^Pay VERY good attention to ANYTHING this guy says!!!

Gunny ionbeam.
Add to the mix...

TB's sinked, plugs ok, airfilter good or replaced, etc. Have you recently done any electrical work on the bike (mechanical or elctrical), battery change, etc?

 

[FJR-TX]

I checked the filter just now, I'm 3/4's of the way through a tank with some seafoam in it. I tried checking the connector but it's a little difficult to open the bike up enough in the parking lot of my apartment complex to get to the main connector. My bike is eligible for the TPS sensor, so I'll be taking it in shortly to have that swapped out and will ask the dealer to check the connector. The bike has some Two Bros slip-ons on it, so somebody suggested it could be running lean. But I'm not sure if that would be it, as I rode the bike for 7k w/o noticing it, so I don't think it just all of the sudden started running lean. Thanks for all the input everybody.