2003 stumble when launching

[ANZAC]

Hello from ANZAC again - this time with an update regarding my bike and the hesitation/stumbling issue. Last time I installed a PC3 but returned it as things never seem to fuel right. Since I had replaced plugs, TPS, fuel pressure regulator and runs lots fuel cleaner through the tank.

This week I saw a posting on the C-14 fourm regarding hesitations and poor fueling. The OP said he reset the TPS by doing the following:

Switch power on only - don't start the bike. Twist the throttle fully open then closed twice.

Switch off power.

Switch on power and ride. My fueling now is perfect. Gone is all the hesitations and chugging below 2000 revs.

Hope this helps others and helps explain why mine was having these issues. I disconnected the battery every time I cleaned the electrical connectors under the t- bar and when I installed/removed the PC3. I would do this every time now if you disconnect electrical power. Seems to work for my 2003 FJR, 2009 C-14 and BMW's too.

 

[Fred W]

This is either a total delusion or...

you may have a TPS (Throttle Position Sensor) issue.

The TPS is a sensor that tells the ECU what the throttle position is... (duh!) But it works based on a potentiometer (variable resistor) which can supply faulty information if it is faulty.

Worth a check, IMO.

 

[ANZAC]

I know it's sounds werid but it worked and nothing else seemed to fix the problem so fully.

The bike has a new TPS that I installed early this year. It's adjusted for the proper range too.

It's worth a try if anyone has these problems

 

[Mihalis fjr]

Very odd and strange,but i will try it!

I have had the same problem and the PCIII has solve about the 90% of the problem..

Remain an about 10% problem..I will try it!

 

[Fred W]

I've seen the same "logic" before in online forums, especially when you have fueling issues.

Just to clarify my earlier response: There is no way that this calibrates anything in the ECU. Our FJRs' ECU does not have any adaptive capability. It cannot "learn" anything by going through this kind of song and dance.

What can happen is that by opening and closing the throttle multiple times you can exercise the TPS and clean the track that the potentiometer wiper travels on inside, temporarily improving the sensor's output signal accuracy. Eventually the symptoms will return. TPSes are known to fail on almost all FI bikes.

 

[ANZAC]

I know it sounds strange but it's worth a try and like Fred said maybe we are cleaning the wiper contacts in the TPS.

Let me know if this works Mihalis and remember that I removed my PC3. The PC3 seemed to work to a certain degree but the bike still had the original problem so I returned it while the return window was open.

Here is the link to our Brothers over on the COG boards:

https://forum.cog-online.org/index.php/topic,54254.0.html

 

[Mihalis fjr]

I will try it,but tell me what map you run in your PCIII?I run the European map and works very good for me.

From what i have heard the Wallys smooth map works very good there in US.

Usually the PCIII solves the problem at about 80-90%..

 

[ANZAC]

I tried the Wally map and the Ryan map that Fred recommend but neither made a big difference. So, the bike is back to stock configuration now with the PC3 out.

The main electrical connector under the T-bar has been cleaned many times and now shot with APC50 for corrosion purposes. I also shot the TPS connector and a slew of other connectors while I had the tank up and battery disconnected.

The bike remains running correctly now after the TPS reset. Perhaps the ECU really does re-calibrate the TPS when performing the procedure. I was not expecting this to work and thought it's worth a shot. Maybe it will help you guys - at least it's free and it was the only thing that really worked for me.

 

[Mihalis fjr]

I will try it!

The most important is that you are happy with this trick and you bike works good now!