Replaced Your Throttle Position Sensor?

[QuikSilver]

I would be interested in hearing from folks who have replaced their Throttle Position Sensors with a description of what symptoms the replacement fixed. I would prefer to hear from these folks first, prior to opening the topic up to broadband speculation as to solutions to my problem.

The problem - I have had a very intermittent stalling problem at idle (or just coming off of idle) beginning at ~ 9000 miles on my '03 FJR. Now with 37,000 miles on the clock, it is occurring more frequently (3 times in 200 miles yesterday), but still difficult to reproduce on demand. "Occasionally" when I have been in slow-moving, stop-and-go traffic (with the engine temp at two bars), as I gradually give the FJR throttle at idle (1000 - 1100 RPM) the RPM will decrease to about 600 RPM and stall. I was able to reproduce it at my dealer today, after about 10 minutes of trying. My suspicion is that when the Throttle Position Sensor gets hot, there is a fine spot in the rheostat where there is an open circuit (or other abnormal resistance) that confuses the EFI computer and sends the wrong mixture.

Regards,

QuikSilver

"Ride hard! You can rest when you die."

 

[04 FJR Pilot]

My dealer told me of a bike he worked on (an 03) that had problems. It would just die. Start it up and it would run for 200 miles and die again. He had to ride it for a weekend to get it to act up. he changed all the sensors to no avail. Finally Mammy Yammy sent him a shiny new computer, The bike was out of warranty but yammy footed the bill cause he had been having trouble with it for so long. I wouldn't even want to know what the computer costs. Hopefully this is not the case with your bike but is a possibility if the TPS doesn't cure your ills.

 

[raclow]

Quiksilver:

I had a problem with what I thought was the cluth but have since considered the problem to be in TPS. I received some good info from my post and maybe it can help you........clicky

Good luck.

 

[SkooterG]

Do you have a service manual? There is a way to get into a diagnostics mode of the ecu that is displayed on the LCD display. I would definitely give that a try. When in diagnostics mode, it may show funky reading for the TPS.

I take it you have NOT been getting any error codes?

 

[ionbeam]

TPS was discussed here. There is a pretty good amount of information that should be helpful.

 

[QuikSilver]

Ionbeam - Great information!

I had no responses to my thread, so I took the FJR to the dealer on Tuesday morning. I suggested to them that I believed I had a faulty TPS. Just before going to the dealer, I briefly looked at the shop manual regarding TPS diagnostics. I found the diagnosis description somewhat confusing and elected not to mess with it due to lack of time.

Even though I had just replaced the plugs and did a throttle body synch, the dealers top mechanic decided to do a throttle body synch, including balancing the butterflies by ear. $90 later, he thought he had solved the problem.

When I got the bike back, the idle was at 1300 -1400 RPM and the intermittent problem still existed. They called their Yamaha Tech consultant who described to them how to do the TPS diagnostic but they claimed not to have the proper equipment. The Tech Rep agreed with my diagnosis of a bad TPS and authorized a replacement . They ordered the part and agreed to reimburse me for the unnecessary throttle body synch. The part should be in next week.

A few minutes ago I followed the clear and simple instructions for TPS diagnosis from your thread. Within 30 seconds, I had results that supported the bad TPS theory. With the throttle closed, the display read 15. With slight throttle openings, the reading dropped to 1 and then had erratic readings for the first few degrees of turn.

I owe you a cool refreshing adult beverage of your choice! Look me up if you ever get to mountains near Albuquerque.

Regards,

QuikSilver

"Ride Hard. You can rest when you die."

 

[Yambone]

Even though I had just replaced the plugs and did a throttle body synch, the dealers top mechanic decided to do a throttle body synch, including balancing the butterflies by ear.

Yikes!