Sputtering - an update

[markusmaximus]

Many of you will recall that a few days ago I posted a thread about sputtering and the FI light on. At times only one cylinder was firing. Many thanks to those of you who responded with suggestions, namely CadmannQ, Cactusjack, Blowndodge, Ells and Rewindgy.

I took her in for service. The service dept at my local Kawa dealer informed me that the diagnostic code points to a faulty throttle sensor. They tested the throttle sensor and found the idle voltage registered .065 V and WOT voltage registered 4.78 V. They adjusted the sensor within specs. The bike ran great after this adjustment.

But given that at times only one cylinder was firing, the service dept call Kawa engineers to discuss. They found over 250 crankshaft sensor failures and vehicle speed sensor failures. Kawa engineers believe a faulty wiring harness around the battery area is to blame. They commented that they are hearing about similar problems with other Nomads.

Since the bike was running great, I decided to take her home, happy that I didn't have to buy a new throttle body (or sensor even) but with some trepidation that these problems may resurface. If so, I'll have the electricals inspected thoroughly. May want to keep this in mind for future reference.

BTW, the dealer was very reasonable with the charge and generally seemed committed to finding the source of the problem, although they seemed perplexed at times. Perhaps they don't see many Nomads. Not a bad thing until it's your bike.

Wow! That is an eye opener.

I wonder if this only affects 1600's? A 1500 has a different wiring harness. If it hits the 1500's too, I'll be under the seat checking out the harness for sure.

Did they say why the TPS changed all by itself? Did it move? Or was it just a matter of wear?

[markusmaximus]

Originally Posted by caddmannq

Wow! That is an eye opener.

I wonder if this only affects 1600's? A 1500 has a different wiring harness. If it hits the 1500's too, I'll be under the seat checking out the harness for sure.

Did they say why the TPS changed all by itself? Did it move? Or was it just a matter of wear?

They didn't say which model was being affected. Nor did they say why the TPS was out of spec. They (the dealer) were genuinely surprised that I asked some very specific questions. I don't think they knew much about it. They were merely following the owners manual. But I made sure to get the voltages this time for future reference.

Say, by aligning the TPS to adjust the voltages down, does that cause the bike to run leaner? I ask b/c I get a little pinging under high rev roll-on. Just curious.

Yes. Typically you want the TPS about 0.03 volts higher than stock to help eliminate pinging.

According to the Guru of All Things Nomad (Mr. Gadget):

"For the record the Kawasaki factory maintenance manual calls for:

0.584 to 0.604 volts with the throttle opening at idle
4.29 to 4.59 volts at wide open throttle (WOT)

As you'll see below Vulcans come from the factory with a substantial variation in settings between those numbers and even .05 volt change can make the difference whether the engine knocks under load or doesn't and may also give you the option of using regular or mid grade fuel instead of premium. "

Look here for the whole story:
http://www.gadgetjq.com/tps_adjust.htm

[dogdoc]

Glad to hear you got your problem fixed MM.

[billmac]

Yeah, glad you got to the bottom of it and let us know the details. Hope your fixed up.

[ells]

Sounds like something we need to be on the watch for. Sounds like CMQ is on the case. High tech stuff, I don't think filing the points is going to help... (I know, I know...)

[skeeter]

Originally Posted by Ells

Sounds like something we need to be on the watch for. Sounds like CMQ is on the case. High tech stuff, I don't think filing the points is going to help... (I know, I know...)

LOL!

[aj]

MM, a good outcome. And a useful discussion
ta

Hey, setting the TPS is just like setting the points with a dwell meter. You loosen a little screw and move the thing until you get the right reading.

[flavor]

All good info.

Thanks