Throttle Position Sensor TPS Part Number

[ARKNT]

Your readings sound consistent. I would probably not go to the coils unless something else sends you there.

Brad


edit:
I did measure some temps at the reg/rec. With ambient air temp at 82 deg F, the R/R was 125 deg, the alt wires were also hot at 160 deg, and the alt cover 175 deg. These were taken after a ride with the bike idling the garage (no air movement). The wires and R/R cool pretty quickly so the readings need to be taken under normal running conditions to give good meaning.

 

[ToddTool]

Hey Brad,

Thanks for the pics and info. Hopefully I won’t need to get in there,

Mark

 

[ToddTool]

Back to the spark plug caps now. When I took the bike in for the cam chain tensioner recall, The shop was going to replace the spark plug caps also. When I picked the bike up, they gave me the old caps in the new boxes, I thought. I found them today and it may be that they forgot to actually swap them when they had the tupperware off. The NGK caps that are in the boxes have the same part no. (SB05F) as is on the box (picture attached). The caps also look brand-new with no scratches, smudges, dirt, or grease.

Does anyone have the original part no. and the part no. of the replacements?

Thanks,
Mark

 

[ToddTool]

Here is what is on the bike
Front

Rear

I also have one VD05FB that was in a box labeled XD05F.

I thought that one was a replacement I bought for the broken one on my Z50R but the broken one is a VD05F with out the B. It fell apart while unplugging it so I went ahead and swapped them out.

I’m confused........HELP!

Mark

 

[ARKNT]

Not sure but I think front and rear caps should be the same. From your pics they may be updated but the service bulletin shows how to identify them hopefully (pg3). I don't know what the dealer gave you in the boxes, they should be 45 deg angle I think.
Attached is bulletin.

Brad

 

[ToddTool]

This is the third time I’ve tried to reply but it keeps disappearing. Anyway, thanks Brad, I’ve been looking for a good copy of that notice but it just does not seem to exist.

The site:
https://www.cmsnl.com/products/cap-assy-noise-su_30700mew922/#.Wy6jv_FOnYV
Has a picture of the 30700-MEW-922 that is called out on the notice as the new replacement and if that is the actual picture and not a stock photo then the VDO5FB is the right one because that is the part no. that is visible if you enlarge the photo.

That is the same no. as the one on the rear of my bike. So it is also the one I just put on the Z50R so I’m going to take it off and put it on the front cylinder of the NT.

I’m not sure what happened at the dealer.


Thanks again,
Mark

 

[ToddTool]

I decided to try your idea Macka and raise the idle voltage of the TPS. I’ve raised it to 0.681v. I started it and it seemed to run fine but I’ll have to put the tupperware back on before I ride it tomorrow. My data aquisition system is still connected so I’ll try to catch “the event” if it happens.

Mark

 

[Macka]

I decided to try your idea Macka and raise the idle voltage of the TPS. I’ve raised it to 0.681v. I started it and it seemed to run fine but I’ll have to put the tupperware back on before I ride it tomorrow. My data aquisition system is still connected so I’ll try to catch “the event” if it happens.

Mark

Good luck! It may just be enough to "cover" the problem without actually fixing it.
Sometimes, a Band-Aide fix will be enough to stop the bleeding without needing surgery.

Macka

 

[Macka]

Hey Macka,
Love the fan. I may go back to the original R/R and install one.

Thanks to all,
Mark

Here is a picture of the installed fan. A little crude, but effective.
It was installed with the LH inner pannier case installed but would be much easier to do with it off!
As you can see, it gets plenty of dust in there.




Macka

 

[ToddTool]

After adjusting the TPS idle voltage to 0.681V I’ve ridden two more times and taken data. The TPS voltage only dropped by 0.010V for a very brief period to 0.671V at idle. That was nothing compared to the previous run where it dropped 0.155V (down to about 0.31V).

I did notice something strange on the 1st run at the higher voltage. There were these little sign wavish blips when coming off idle and also during acceleration. I thought that it may be interference from the Idle Air Control Valve due to it’s close proximity to the TPS and that it would likely adjust when coming off idle. Those short blips were also on previous runs so I just knew I had solved it. See waveform attached.


I then connected both of the IACV coils to the data system and rode again. see attachment.



The IACV signals are lagging the TPS “disturbance” so they could not be the cause. Data is great if you can interpret it. Finally it sank in that the “disturbance” was me. I have a habit from 2 stroke motocross days (70’s) of giving two short throttle blips before rolling. You had to keep those bikes cleared out and put a little momentum in the flywheel. The other blips during acceleration and deceleration are when I changed gears.

I’m going to take data one more time when the outside temp gets in the 90’s F since the MIL 8 seemed to be more prevailent at higher temps.

The higher idle voltage does not seem to have any bad effects so far so I’ll just leave it for now.

Mark

 

[Macka]

Hopefully you might be on top of the problem now.
If this (adjustment) does solve the issue it will probably help other people who have had a similar problem.
It certainly would be a cheap fix for a common issue!

Macka

 

[Tourguy]

I have NO idea how to adjust the voltage to the TPS . . . am not educated in the ways of DC equipment and testing procedures. This has probably been obvious. Perhaps is unreasonable for me to ask a more simple summary of what has been discovered.
I'm posting again about my riding experience with this issue on a slim chance it could help:
After a few rides I find that the TPS MIL light is finicky . . . more likely to be on early in the ride, but if I stop and restart the engine perhaps 3 times I can complete the ride with the MIL staying off. Rode yesterday for about 20 mi after intermittent MIL lighting [I stop and start]. I rode some of this with the light on but it stayed off after about the 4th restart. I have also been working the throttle with ignition off and on during these times.
I wonder if giving up by throwing down the cash to replace my throttle $$ will fix this or leave me in a greater but poorer state of frustration. Possibly would already be there [frustrated] if not for the input of others posting here at the org. Thanks for your efforts.

 

[ARKNT]

Problems like these intermittent failures are the most difficult to fix. Seeing what others have done is a big help but still doesn't make it easy.

Brad

 

[ToddTool]

I have NO idea how to adjust the voltage to the TPS . . . am not educated in the ways of DC equipment and testing procedures. This has probably been obvious. Perhaps is unreasonable for me to ask a more simple summary of what has been discovered.
I'm posting again about my riding experience with this issue on a slim chance it could help:
After a few rides I find that the TPS MIL light is finicky . . . more likely to be on early in the ride, but if I stop and restart the engine perhaps 3 times I can complete the ride with the MIL staying off. Rode yesterday for about 20 mi after intermittent MIL lighting [I stop and start]. I rode some of this with the light on but it stayed off after about the 4th restart. I have also been working the throttle with ignition off and on during these times.
I wonder if giving up by throwing down the cash to replace my throttle $$ will fix this or leave me in a greater but poorer state of frustration. Possibly would already be there [frustrated] if not for the input of others posting here at the org. Thanks for your efforts.

Don,

I hope really hope that raising the idle voltage is going to make my bike usable again. As Brad said, these intermittent problems are very difficult to resolve. I wish I was more confident but only time will tell.

Perhaps if several of us try this then we can find out quicker if it is a viable work-around.

I adjusted the TPS voltage by loosening it’s mounting screws and rotating it counter clockwise. Since I had already replaced my TPS, I had already removed the shear-head torque bolts and replaced them with sockethead button screws so that would be the first thing you would have to deal with. Just getting to the TPS is fun and a workshop manual is recommended. It may be easier to adjust to a resistance rather than a voltage. Next time I work on it, I’ll disconnect it and measure the wiper to return resistance.

Another approach may be to adjust the throttle stop, if it has one. Does anyone know? Another possible temporary test may be to adjust the throttle cable at the twist grip and take the slack out until the idle increases several hundred RPM. Issues with this may be that it will rev when the bars are turned to extremes or the RPM may drop when the bars are turned. However, it may be worth a shot before digging down to the TPS. Does anyone else have thoughts about this?

Mark

 

[Macka]

Don,

I hope really hope that raising the idle voltage is going to make my bike usable again. As Brad said, these intermittent problems are very difficult to resolve. I wish I was more confident but only time will tell.

Perhaps if several of us try this then we can find out quicker if it is a viable work-around.

I adjusted the TPS voltage by loosening it’s mounting screws and rotating it counter clockwise. Since I had already replaced my TPS, I had already removed the shear-head torque bolts and replaced them with sockethead button screws so that would be the first thing you would have to deal with. Just getting to the TPS is fun and a workshop manual is recommended. It may be easier to adjust to a resistance rather than a voltage. Next time I work on it, I’ll disconnect it and measure the wiper to return resistance.

Another approach may be to adjust the throttle stop, if it has one. Does anyone know? Another possible temporary test may be to adjust the throttle cable at the twist grip and take the slack out until the idle increases several hundred RPM. Issues with this may be that it will rev when the bars are turned to extremes or the RPM may drop when the bars are turned. However, it may be worth a shot before digging down to the TPS. Does anyone else have thoughts about this?

Mark

My TPS does not have "shear screws", just normal Torx screws.
I would not recommend the resistance method as the ECU is only interested in voltages. Resistance as a reference would be interesting but not useful, I think.
DO NOT touch the Throttle Stop Screw or the Balance (Synch) Screw. You will just create problems for yourself.
Reducing the slack in the Throttle Cable can have unfortunate consequences when turning sharply!

Macka

 

[DirtFlier]

When I bought my bike in Dec 2009, I purposely increased the throttle cable freeplay because it was just too jumpy for me when trying to hold a steady speed so I can't imagine the freeplay being used as a throttle stop adjuster!

 

[ToddTool]

Thanks for the responses/warnings but as a quick test I do think taking the slack out of the throttle cable to raise the idle RPM is worth a shot. Don’s bike is getting errors almost continuously so it might be worth the annoyances to try this because it is easy to do and he would see results right away, potentially. I most certainly would not recommend this as a solution but if it gives a good result, he could then move on to more difficult attempts.

I believe it was on this site that I read that some of the bikes were sent with the shear head torque bolts and others just had socketheads or Torx. I was not one of the lucky ones but fortunately mine were not very tight or seized up so they came out fairly easy.

As to the resistance adjustment, it can be done but I do agree that the voltage is a better indicator. The TPS is a variable resistor acting as a voltage divider so the voltage is actually derived from the resistance. That being said, the ECM pulldown resistor along with the impedance of the input circuitry do have to be considered for a very accurate resistance adjustment. However, if anyone has problems reading the voltage, which has to be done with everything connected and powered up, I can explain a close approximation method of adjusting to the resistance of the TPS while it is disconnected from the wire harness and everything powered down.

Edited: I should also mention that rotating the TPS to raise its voltage is not exactly the same as raising the idle speed by pulling out the slack in the cable. Pulling the slack out actually moves other things in the linkage besides the TPS (maybe Macka can elaborate). If you do try this just be careful and be cognizant of the kill switch.

Mark

 

[Macka]

By taking the slack out of the cable you will slightly open the throttle plates at idle which should not be done as this small calibrated air leak gives the ECU the "Base Idle" from which the Idle Speed Control starts to adjust to keep the idle at the target level (1250 rpm). Basically, you will stop the ISC from doing its job.
A tight cable will also raise the TPS voltage above 1 volt at which point the ECU says to the ISC, "I don't need you now".
The usual result is a severely "hunting" idle or no idle at all.
I have not tried it on the NT but those symptoms would be typical of a TPS with too high voltage at closed throttle.
On the other hand, a dirty throttle body robs the ECU and ISC of the Base Idle which means that the ISC has to go to near or actual 100% Duty Cycle to try to raise the idle to 1250. This usually results in a low idle speed and stalling.
Everything relies on everything else being at known values to operate correctly. Upset one and you often get unexpected problems.

Macka

 

[ToddTool]

Yeah, what he said.

 

[ToddTool]

I finally got to ride again and take data on a hot day. It may have just been coincidental but it seemed that when I was getting the most mil 8’s before, it was hot outside. Today it was in the 90’s F and it was muggy. I set the data sys to log for 40 minutes and took off. I rode down a winding country road and then down the Lynchburg highway down to the Jack Daniels distillery, turned around at the visitor center and headed back home. I must have ridden for an hour because the data sys stopped before I made it home. Anyway, the 40 minutes of data showed that the TPS voltage never fell below 0.67V and no mil’s.

Now I will take the data sys off and see if the mil’s come back. In physics, the observer effect is the theory that simply observing a situation or phenomenon necessarily changes that phenomenon. This is often the result of instruments that, by necessity, alter the state of what they measure in some manner.

I took a couple of pictures of my old TPS screws for a reference. There is no hole or socket or hex or Torx on the head unfortunately. The cuts on the outer edge is where I gently rapped on them with a small hammer and small chisel in a counter clockwise direction to loosen them. Be very gentle if you do this. The screws were not very tight but they are screwed into ears that protrude from the throttle body and I would sure hate to break one off. Other options are to file a slot in the head for a screw driver blade.



Mark