| Author | Message | ||
     Gradeabeef |
I have searched the archives and found the TPS reset works for almost everyone. I have attempted the TPS reset procedure multiple times with no luck. seriously like 10 times. Fast, slow, just right, holding for a second, 2 seconds, 3 times 4 times. day, night, hot, cold. I get 2% closed and 92% (3.5 volts). I have had the air box off while doing it to ensure the plates are opening all they way. From what I can tell they are perfectly straight up and down. I have not attempted to adjust the cable or stopping point because they look as though they would start to close again if they rotate any further. I don't have the breather hose rubbing either. Im not sure why the reset procedure does not work or at least give me 100% (3.9 -4.1 volts) at WOT regardless of the plates position. Im about to start pricing a TPS if I cant find another option. | ||
| Stevel |
I don't understand your problem? A TPS is only a linear resistor and simple enough to check with a VOM. Sounds like you are chasing a non-issue. | ||
| Reepicheep |
The TPS reset doesn't reset the TPS, it tells the ECM what TPS reading is "closed". That way individual variations or gradual drift in the potentiometer don't matter. You just recalibrate. It should be reading consistently though, closed should be the same reason if you let it flap shut 10 times in a row. If that's not the case, then it is failing. That isn't very common, but being mechanical, potentiometers aren't the most durable of electronic devices. | ||
| Nobuell |
Connect an old analog multi meter and cycle open and close. You can tell watching the indicator if there are bad spots or irregularities. I always keep a cheap analog unit on hand for that reason. Much harder to do with a digital readout. | ||
| Gradeabeef |
I'm not sure how this is a non issue, If the TPS never reads 100% How can I be sure the ECU knows I wanna go fast? Im talking like Tom cruise in Top Gun fast. Does the TPS tell the ECU how much fuel the injectors spit? My concern with this is that if the ECU thinks the throttle is at 92% WOT its only sending 92% fuel all while getting 100% air. So now, not only am I hindered by less fuel but the fuel to air ratio is a leaner mix that should be? | ||
| Gradeabeef |
I really just want 3.9- 4.1 volts. | ||
| Stirz007 |
I'd go through the simple stuff again. Of all the gremlins I've chased, more often than not it's something obvious I just missed. Pull the airbox and go into diagnostic. Cycle the throttle while having eyes on the butterfly, linkages, etc. I'd double check nothing is binding and that WOT is indeed WOT. Other than that, weak electrical connection could result in minor voltage drop (resulting in 92% reading at WOT). I haven't seen a lot of TPS failures, but it could happen. TPS does tell ECU how fast you want to go, so one thing's for sure: 100% fast is faster than 92% fast. | ||
| Stevel |
There seems to be some misunderstanding here. The TPS in the first place is a band aid. The ECU really wants to know how much oxygen the engine is ingesting. In automotive circles, mass air sensors (MAS)are also used along with a TPS. MASs can be elaborate, but most use a simple Ni-chrome wire and track the cooling effect of the air charge for density and moisture content. Some also use a calibrated trap door that operates another linear resistor. In all these cases, these devices are making a wild ass guess and ultimately, the ECM must calibrate itself to the sensors via the Lambda sensors in the exhaust. Consider the TPS and MAS to be the immediate feedback to the ECM and the Lambda to be the post event calibrator. In this light, you should realize that whatever the feedback voltage of the TPS is at WOT, the ECM will deal with it as long as its operation is linear. You have just assumed that if the TPS voltage was higher, you would have more WOT power, which is patently false. If you really want to know what's going on, you need to use a pair of wide-band Lambda sensors and a data logger. | ||
| Nobuell |
As Stevel said, the ECM wants to know what the span is from closed to wide open. The actual value is irrelevant unless the span is out side of the range programmed within the ECU. Are you getting any codes? The manual identifies the voltage at idle will be approximately.0 -1.0 volts and 3.5 - 4.5 at WOT. Looks like you are within the range, all be it on the allowable low side.. | ||
| Pgh_biker |
so TPS reset lets the ECU know what voltage to use for Min and Max throttle based on what your throttle tells it when it's at the min and max settings? | ||
| Nobuell |
Yes, setting the TPS means telling the ecm what the min and max is for your particular bike. Every one will be a little different. | ||
| Nobuell |
We use rotary pots at work for valve actuator positioning. It is the same as the bike. The open and closed span is programmed into the digital controller. In the case of the actuator, the amount of rotation varies based on the particular valve it is mounted on. Same process though. | ||
| Skntpig |
This is from EBR for the RX but not in the manual. After the 3 closed and open you need to shut off the ignition key and wait at least 2 seconds. Then turn on and start after the engine light is out. | ||
| Dualbuells |
American sports last I checked for TPS is out of stock through HD if I remember correctly. Twin has them for like 65pounds or so. I'm having issues with doing the TPS on my 08 1125R, had a minor load side last fall cause of the TPS went south for some reason. Trying to get it sorted out so I can take her to the track at Grattan Raceway this year. I'm gonna attempt the reset again, this time I'll try Skntpig's method, hope it works. Seems odd that the tps would go, I think I only have like 18K miles on the 08'! | ||
| Ratbuell |
The TPS is a volume knob. The reset procedure simply tells the ECM "when you see this voltage value, the knob is all the way up (or down)". That's all it does. | ||
| Xtreme6669 |
Make sure you have the key on AND the kill switch set to RUN. Then try it again and I bet you get the full range. | ||
| Dualbuells |
Minor HiJack - I did the TPS and according to the diagnostics the setting is now 2 closed and 100% at WOT. Seems as though while riding if I'm hard on throttle the throttle responds ok, but if engine braking occurs a little and I crack the throttle it like lags on the throttle then just takes off like a bat out of Hell. Very disconcerting whilst in a corner, thats what it was doing when I low sided late last year on it. Any suggestions of other things to check? | ||
| Stevel |
Dualbuells, It is almost a certainty that your TPS has a flat spot or perhaps even an open circuit at certain positions. Linearity is absolutely critical where the resistance of the TPS changes proportionally with its angular change. Sounds like you need to change yours and since they are not sold separately, you will have to buy a new throttle body. | ||
| Dualbuells |
Steve thanks for the input! I found the TPS at Twin Motorcycles for like $78.00 and they have it in stock. I also found on flea-bay the throttle body with the TPS for $109, I put a bid in on it for $65.00 plus shipping of $12, nothing ventured, nothing gained I say! LOL Thanks for the help! | ||
| Stevel |
Dualbuells, This type of problem will become much more severe in the future, as EBR is toast and HD will most likely drop support for the 1125 next year. (7 years) The TPS was initially supported as an individually replaceable part, but that is no longer the case. I have a couple of spare throttle bodies around. Perhaps now is a good time to figure out how to replace the resister and bearing with commercially available equivalents. Does anybody know how many of these engines have been sold? | ||
| Hughlysses |
If it's just a potentiometer, why not try spraying the innards with contact cleaner? | ||
| Stevel |
H, Cleaning the TPS might work, but if it doesn't, it could spit you off the bike. So the argument comes down to a new resistor or potentially Honda Rash or worse........your call. I know what side of the argument I would be on! | ||
| Smoke |
dual, have you disconnected the epa solenoid and wired the throttle body control mechanism together at the rear throttle body on the left where it can separate from the front throttle body mechanism? that solenoid is known for inducing lag at throttle application as it closes rear throttle body while you are asking for more fuel. tim | ||
| Dualbuells |
I have not bought the TPS from Twin, I will have to try cleaning it first. Smoke - I did remove the solenoid but didn't do the wiring of the throttle control mech., which leads me to another stupid question: if the resistor went bad what would happen? Have I caused a problem by not wiring the throttle mech together? I will have to look at it, if any body could post a picture of where it is tied together would be helpful, but it might be obvious once I open it up. Thxs | ||
| Nuts4mc |
picture 13, I believe http://www.badweatherbikers.com/buell/messages/290 431/490767.html | ||
| Dualbuells |
Nuts4mc - thanks! I will make it happen with a zip tie! | ||
| Nuts4mc |
...I would use safety wire/mechanics wire....the heat the engine gives off could cause the zip tie to fail over time...hope this helps | ||
| Nobuell |
Why the zip tie? How can the linkage change without the tie? Never had an issue on the track bike. What am I missing? | ||
| Nuts4mc |
NoBuell...I believe one of the butterflys are "free" to do what they want if you do not tie them to the linkage...If I remember the solenoid closed the butterfly(s) in 3rd gear at WFO to meet a noise requirement by the EPA....yes there are springs that are supposed to make butterflys work as one, but a spring is not a "solid" link to the throttle action...that is why it is "smarter" to safety wire the linkage then to depend on a spring...hth | ||
| Zac4mac |
The butterflies are hard-linked to each other but both are spring-linked to the throttle. If you don't tie them, they will both flutter at high rpm at the cost of 3-6 HP. Z OOps BTW - I use standard 3-4" nylon zip-ties. Cut Loretta's a couple of months ago to verify engagement and fine since 2008. (Message edited by zac4mac on April 30, 2015) |
