Indicators for bad TPS

[VEGASRIDER]

So I have read this thread in it's entirety and without actually doing the diagnostic test, which is on my list to do, I have come to a conclusion that my TPS is beginning to fail? But my symptoms have not been consistent with the others, but similar on some other issues.

http://www.600riders.com/forum/fz6-...ou-experiencing-poor-idle-mileage-stalls.html

1. Poor fuel mileage, but not that bad. But maybe 20-30 difference per tank.

2. Bike will not maintain a steady speed or rpm, especially in the lower gearing, such as 2nd. It's like a constant jerking motion. Not so bad once I pick up speed or get into 5th or 6th gear. Someone mentioned a clogged air filter, but I just cleaned mine (K & N) this winter.

3. My bike does not stall or have an irregular idol. However, on a few occasion coming off a very high RPM while riding, the bike did stall. But this is far and few between. It started up without any issues. No error code indicated as well.

My bike is 2006, so it's wasn't part of the recall.

Your thoughts?

 

[FinalImpact]

^^ Yours almost sounds like gas quality, i.e. water in fuel??? So you're saying over the last 2 or 3 tank fulls its getting 20 to 30% less MPG?

1st thing that comes to mind; When is the last time the Spark plugs were checked? Do they have more than 15,000 miles on them or are they iridium? If more than 15k on stock CR9EK's this alone could be the issue.

If TPS checks out, these could all be a factor:
Air filter is oil saturated & Dirty (Poor MPG, Stall on throttle chop), Clean it, use less oil
Worn spark plugs (stalling, MPG, engine missfire under load), Replace, CORRECT GAP!
Low idle speed (stalling, NOT MPG), Adjust
Poor fuel quality (stalling, mpg, variable RPM), New Source + Gas Dryer
Vacuum leak (stalling, mpg, variable RPM), spray TB area with starting fluid, does it change RPM?

 

[Motogiro]

Also as has been discussed FI and I before, the resolution or noise created by a faulty TPS may not show up in the onboard test or an ohm meter. I had a member here who had a bad TPS on his car. The ohm meter test passed it but because everything else seemed to point at the TPS we replaced it. The car stopped it's jerky behavior and was smooth again.

Here's a perfect place for an oscilloscope to be used to see that noise. :rockon:

With the mileage Kenny has on his bike I'll bet he's wearing a hole through the TPS! Lol!

Kenny,
How many mile on that FZ6 now!

 

[VEGASRIDER]

This has been going on for months. I don't think it's a gas quality issue or plugs. But I guess the plugs has around 15-20k miles, but my last set of Iridium went over 50k miles, and were replaced by choice, since the head was already removed anyways.

Wonder how much a TPS cost?

 

[VEGASRIDER]

Test was 16 and 101, now what?

 

[Motogiro]

Test was 16 and 101, now what?

How many miles on your TPS?
Your bike is high miles correct?

As I said before , it may pass the onboard or ohm meter test but still be noisy to the ECU. It would be nice to have someone with an O'scope look to see if it's noisy.
I'll research a price...

Sent from Moto's Droid using Tapatalk 2 :mikebike:

 

[VEGASRIDER]

91k miles. Now I thinking pinched fuel line, faulty gaps on the plugs. Like I mentioned, zero issues on the idle and no stalls. Just real jerky while trying to maintain a steady speed.

 

[Motogiro]

I have an email out to RonAyers.com because I can't find the TPS on their drawing. I've asked for a price and part number.

If you feel you have a fueling issue regarding a pinched line of a weak fuel pump you can get it pressure tested to eliminate it. Also not a bad idea to run some sea foam with your fuel for a few days. I've seen it clear up terrible throttle response and stumbling.

 

[Motogiro]

See part number 10 on the drawing. Not cheap for such a little part. Here it is: INTAKE 2

Part no. 5FL-85885-02-00

I hope it's just dirty injectors...

There is a manifold pressure sensor that can also cause the same symptom.

 

[TownsendsFJR1300]

Test was 16 and 101, now what?

When you checked the #'s, you did look at ALL the #'s inbetween, no skipping, etc? You may also want to get the bike hot, then go again into the TPS mode and check it again. It may change when hot..

I'm wondering (besides the possible clogged injectors) that you may have a vacuum leak somewhere, (the intake boots?) between the head and throttle bodies?

The high vacuum coming down from high speed run would suck more air into the engine and cause it to lean out and stall. With that many miles on the bike, the rubber boots are likely to dry out and not seal fully.

Spraying some carb cleaner (a little at a time) at each boot and listening for a rise in the RPM's would indicate the boots are failing. Even looking at them with a good flashlight may show any cracking (which there shouldn't be any)

 

[VEGASRIDER]

When you checked the #'s, you did look at ALL the #'s inbetween, no skipping, etc? You may also want to get the bike hot, then go again into the TPS mode and check it again. It may change when hot..
)

I will try this suggestion, doing the test when the bike is hot. It was done when the bike was sitting for about an hour. And I will make sure to go through all of the numbers, which I did not. I was just looking for the min and max, thought that all it mattered.

It couldn't be due to a bad chain and rear sprocket? My chain is toast. Tight on one side, slacking on the other and kinked up. I plan on getting this swapped out this week, but not sure if the jerking motion at the lower speeds had anything to do from that.

 

[TownsendsFJR1300]

I will try this suggestion, doing the test when the bike is hot. It was done when the bike was sitting for about an hour. And I will make sure to go through all of the numbers, which I did not. I was just looking for the min and max, thought that all it mattered.

It couldn't be due to a bad chain and rear sprocket? My chain is toast. Tight on one side, slacking on the other and kinked up. I plan on getting this swapped out this week, but not sure if the jerking motion at the lower speeds had anything to do from that.

A bad chain, especially if its that badly seized up can certainly cause that jerkiness and likely is. It also tends to make considerably more noise. IMHO, don't cheap out, but buy a high quality DID X ring chain or other name brand, top of the line chain.. I'd be changing that (and likely sprockets) first before looking for other issues.

And yes, the #'s inbetween are extremly important.

You can adjust the TPS for the high # to be higher for a slightly richer mixture. Yamaha Headquearters in California, had my local dealer bump it up some when I was having some issues with my old FJR. Basically, all it does it tell the ECU that the throttle is open farther than it actually is slightly richening the mixture (the 04 FJR was extremly lean up to 3k from the factory). (That wasn't the issue, a corroded connector under the tank that Yamaha couldn't find, was the issue)

 

[VEGASRIDER]

A bad chain, especially if its that badly seized up can certainly cause that jerkiness and likely is.

Yes, you are correct. The new chain has significantly reduced the jerkiness. But the bike is still sputtering. I mentioned no irregular idle or stalls but my bike is jumping from 1260 to 1320, rpm at idle, back n forth. Is that normal or should the rpm on the idle stay consistent?

 

[TownsendsFJR1300]

Yes, you are correct. The new chain has significantly reduced the jerkiness. But the bike is still sputtering. I mentioned no irregular idle or stalls but my bike is jumping from 1260 to 1320, rpm at idle, back n forth. Is that normal or should the rpm on the idle stay consistent?

I'm assuming it idled smoother before?

The variation isn't really that large. I've read some bikes with that variance, others with less..

I have my idle purposely set low at 1,000 and the needle is dead steady at idle. With that said, I do have the TB's adjusted within 2-3 MM's (spec's allow 10mm's) and do run a fuel additive regularly which I believe helps with the crap fuel we have now a days.

IMHO, I would run either some Chevron Techtron or Yamaha makes a product called "Ring Free" which I use mostly in the boat but also in the bike on occasion. Again, IMO, I'd run a heavy dose of Ringfree as I suspect the irregular idle is fuel related. It really works well: http://www.fjrforum.com/forum//index.php/topic/152932-easy-fix-for-rough-idle-and-stalling/ It cleans the fuel system as well as the top end of the engine. This particular link, the user does use 2x the amount suggested for a shock treatment with excellent results..(For $10.00, it can only help, there are NO downsides)...

If the fuel additves don't seem to help, a TB sync may help depending on how far out they are, spark plugs/ plug caps should be checked. Of course the TPS could be failing, it does pass the manual check, but as Cliff mentioned, it could still be failing...

 

[FinalImpact]

Lookie - we did this before once..... Blah

 

[VEGASRIDER]

Yes Randy, we did and it's proof that it's been going on for over a year now. The new chain helped and it wasn't as noticeable versus the old worn out chain.