Sputtering; need your advice

[markusmaximus]

About a week ago I posted a thread about my Nomad sputtering and the FI light on. When the battery is disconnected it resets and runs ok until the rpms get too high or the bike is under load, then the sputtering resumes. At times only one cylinder is firing.

The service dept at my local Kawa dealer test rode the bike and confirmed what I already knew (and told them). At first they questioned why I did a baffle-ectomy and suggested this may be a contributing factor. I don't buy it. After several hours of investigative work, they informed me that the diagnostic code points to a faulty throttle sensor, although they will not know for sure until tomorrow. Apparently this is unusual for FI Nomads. So here are my questions. Keep in mind I'm not very mechanically inclined.

1. Where is a throttle sensor and how might this be the cause?
2. How much might I expect to pay to replace the throttle sensor?
3. Is it normal for motorcycle dealers to charge several hours of labor for diagnosis when the code could have been readily accessible? BTW, they've had the bike going on 4 days now.

Any insight is greatly appreciated.

The throttle sensor is on the front end of the throttle shaft, on the front side of the throttle body.

It tells the computer how far you've opened the throttle.

No clue about the $

It is common for the dealer to screw you over as much as possible.

By the way, it is common for those error codes to lie to you. The computer is only so smart. My car was telling me: "idle air bypass solenoid out of range". Well it was. It was going right to the stop, but not because it was defective. I had a vacuum hose loose and it was trying to compensate. (Unsuccessfully)

Also, the most common cause of this high speed missing on Nomads is a bad battery connection. It might not be on the battery end of the battery cables. It might well be a loose wire or loose plug or loose relay on the fuse panel.

One of our members was recently having a similar problem & it turned out his cooling fan sensor wasn't plugged in correctly & was it confusing the computer.

OK, THIS is disheartening. I do not find a listing for the throttle position sensor in the parts manual. You can see it attached to the throttle assembly, but not listed as a seperate part. The throtttle assembly you do NOT want them to sell you. It's $1000!!!!!

[cactusjack]

I've spent the last 30 minutes looking at my Nomad service manual and Ron Ayer's parts microfiche, and I can't find a part number for that sensor. I found it, it's on the throttle body assembly, but I don't see a specific part number for it.

If the throttle position sensor is what they mean, the manual states that it should not be removed or adjusted because it (and I quote) "is set with great precision at the factory". So it may not be available separately.

[blowndodge]

Thats just wrong!

I'm looking at the service manual and if the values fall outside 4.29-4.59 replace the throttle sensor AND the throttle body!! OMG.

If you look at the picture of the TPS you can see there is writing on it but I can't make it out!

[cactusjack]

Boy, this makes me want to run right out and adjust my TPS! With my luck I'd short the dang thing out with the test leads and have to replace the throttle body.

I think I'll go grab a cold beer instead.

[ells]

This doesn't help Markus, but - Nor do they sell the little black reset buttons on the speedo shroud separately either, they sell the entire shroud even though the buttons can be popped right out. That's Ma Kawa not the dealer.

Might be a little unfair, CQ, to claim all dealers are out to get you, I've had some good experiences with one nearby even though I have never bought a bike from them and I regularly do business with an independent who I trust entirely. Decided long ago that most these modern computerized machines we ride in and on are largely too complex for me to try to dig into to much other than a few simple mods, add-ons, and some routine maintenance.

Sorry to hear about the problems you're having, Markus, if it were me I'd be going through the thing you are. I suspect not many independents are well equipped to deal with those kind of problems either. I would double check the battery connections though if that has not already be done.

This makes me want to run right out and sell my Nomad!

No, J/K.

I'm pretty sure that Kawasaki doesn't manufacture the TPS. It probably uses an out-of-the-box part supplied by a Jap electronics firm.

If you took it to a foreign parts shop they might be able to look at it and give you a clue but I wouldn't do that at this point!

First thing I'd do is some research with Gadget, on Delphi, Beartooth, VROC, etc, and see who's already done this and figured it out.

No sense disabling your bike just to re-invent the wheel.

...Might be a little unfair, CQ, to claim all dealers are out to get you,...

I didn't. I just said it was common. I know it's not universal.

BTW, I've replaced TPS's on other vehicles, and they were around $60 or less. They do wear out, and I can't imagine Kawasaki not selling this part seperately. I'm willing to bet that it has something to do with emission certification laws.

[cactusjack]

BTW, I've replaced TPS's on other vehicles, and they were around $60 or less. They do wear out, and I can't imagine Kawasaki not selling this part seperately. I'm willing to bet that it has something to do with emission certification laws.

Hey Cadd, remember the good old days when you could set the point gap on a Chevy engine with a matchbook cover?

[cactusjack]

This makes me want to run right out and sell my Nomad!

No, J/K.

I'm pretty sure that Kawasaki doesn't manufacture the TPS. It probably uses an out-of-the-box part supplied by a Jap electronics firm.

If you took it to a foreign parts shop they might be able to look at it and give you a clue but I wouldn't do that at this point!

First thing I'd do is some research with Gadget, on Delphi, Beartooth, VROC, etc, and see who's already done this and figured it out.

No sense disabling your bike just to re-invent the wheel.

Definitely. Perform some due diligence and look around. It may not be as bad as you think.

I could set 'em by eyeball and ear.

I do think someone in the history of the FI Vulcan has worn out a TPS and NOT bought the whole dang throttle body.

Our task is to find that man. :)

[markusmaximus]

Boy this is dis-heartening. But this is why I checked here first. I'm not going to get suckered into purchasing an entire throttle body assembly. I did check Gadget's page and found the link below to adjusting TPS manually. At least this gives me some insight and a frame of reference when discussing this with the dealer. Also I'll push to r/o other issues that have been mentioned such as battery cable connections, fuel relay connections, loose plug, or loose cooling fan sensor. I'll keep everyone informed how this turns out. ITMT, keep your suggestions coming.

http://www.gadgetjq.com/tps_adjust.htm

[blowndodge]

MM. If the TPS is out of range it still wouldn't be doing what your experiencing. Cutting out is most likely the battery terminals loose or something else. The TPS governs the timing and mixture and I can't see how it would effect only one cylinder running.

No I don't either. Now one defective or partly plugged injector might. Also one sub-par ignition coil might as well.

As for the TPS thing, again codes from the computer can be highly misleading, and dealers can be highly misleading as well.

I had a cracked intake manifold on my Bonneville and I didn't have time to diddle with it because my Mom was in the hospital. Normally, NOBODY else works on my vehicles, but I took it into the dealer to have the manifold replaced and get the car smogged.

Big mistake.

After spending a whole day changing the manifold they told me it wouldn't pass smog. It had a bad code from the TPS and the catalytic convertor was shot.

I took it out and blew it out on the freeway, took it to another mechanic & it passed inspection with flying colors. That was six years ago, and it's passed inspection twice since then, with flying colors. The only repair I had to make to the emissions system in 12 years now has been a vacuum hose, a fuel pressure regulator, and a new gas cap.

But 6 years ago a crooked dealer was willing to screw me around for $800 to change a TPS and a converter that I obviously did not need.

Before you shell out any big bucks for these repairs, get a second opinion.

[markusmaximus]

MM. If the TPS is out of range it still wouldn't be doing what your experiencing. Cutting out is most likely the battery terminals loose or something else. The TPS governs the timing and mixture and I can't see how it would effect only one cylinder running.


No I don't either. Now one defective or partly plugged injector might. Also one sub-par ignition coil might as well.

As for the TPS thing, again codes from the computer can be highly misleading, and dealers can be highly misleading as well.
Before you shell out any big bucks for these repairs, get a second opinion.

CQ, BD,
You guys rock. Just knowing a bad TPS would not cause only one cylinder to run makes sense. Seems like a bad injector would read a code 41 or 42. But what is puzzling is how can dis/reconnecting the battery result in improved performance initially if an injector was bad? Seems electrical to me, but then I'm merely WAG-ing it. Stay tuned!

If the injector was electrically bad it could set a code. If it is physically plugged or distorted it wouldn't.

[rewindgy]

Probably not gonna help - remove Injectors - soak the s--t out of them in Seafoam - check all connections - especially the big one from the ECU to the injectors ( mine had been broken by Stealer when they installed the PCIII)- found my pins to be green - this caused all sorts of wierd things to happen!!!