# 750 wont idle!!!!!!!!!!!



## kawi27 (May 19, 2010)

on my 08 750i the moment i let off the gas at idle it shuts off. does anyone know how to turn the idle up or what the problem may be


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## kawi27 (May 19, 2010)

when the bike is cold it runs perfect but once i go for a ten minute ride and stop it wont idle at all


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## wyo58 (May 13, 2011)

Stock ECU?


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## hp488 (Sep 23, 2009)

Check your tps


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## kawi27 (May 19, 2010)

ya i just changed my voltage regulator thats all


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## filthyredneck (Feb 10, 2010)

Like stated above, check your throttle position sensor. Its located on the right hand side of the throttle bodies, kinda behind the gear shifter. Must have a tamper-proof torx bit to get it off, I want to say its either a T22 or T25 but dont hold me to it. If the sensor is good, you can clock it and make the motor idle up, I had done it to mine awhile back so that I can get off of it in the water to help others and not worry about it dieing.


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## lilbigtonka (Dec 30, 2008)

filthy what ya mean you clock it up so it doesnt die in water...you mean turn your idle up or actually do something to the tps.....


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## filthyredneck (Feb 10, 2010)

The tps is grooved about a 1/4" or so where the mounting screws go through it for adjustment, you can clock (twist) it one direction and the idle will lower, twist it the opposite direction and it will idle up. Obviously, I'm sure this tampers with fuel mixture so I'd recommend plenty of air coming into the motor, and it will also make your bike grind in and out of gear or hard to get in or out of gear if you turn it up too much, but it will work great to just get a little higher idle out of it. If its set too low, the engine may idle fine but may die when coming from WOT and releasing the gas to slow to a stop (i.e. "wheelies") I had this prob for a short while, but have it set just about perfect now. I found this out accidently after installing a new tps several months ago and the motor was idled up waaay too high, and I had to tinker with it to get it right, and then I figured what the hell, since the efi's dont have the idle knob like the carb'd brutes so I adjusted it to suit my needs.


*NOTE: I did find this worked better if I clocked the sensor with the engine off and then snug the screws up and fire it up. I tried while it was running and didn't get the same results and the motor started running crappy. I guess it throws the computer off when you mess with it while the motor's running.


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## LM83 (Jul 23, 2010)

filthyredneck said:


> The tps is grooved about a 1/4" or so where the mounting screws go through it for adjustment, you can clock (twist) it one direction and the idle will lower, twist it the opposite direction and it will idle up. Obviously, I'm sure this tampers with fuel mixture so I'd recommend plenty of air coming into the motor, and it will also make your bike grind in and out of gear or hard to get in or out of gear if you turn it up too much, but it will work great to just get a little higher idle out of it. If its set too low, the engine may idle fine but may die when coming from WOT and releasing the gas to slow to a stop (i.e. "wheelies") I had this prob for a short while, but have it set just about perfect now. I found this out accidently after installing a new tps several months ago and the motor was idled up waaay too high, and I had to tinker with it to get it right, and then I figured what the hell, since the efi's dont have the idle knob like the carb'd brutes so I adjusted it to suit my needs.
> 
> 
> *NOTE: I did find this worked better if I clocked the sensor with the engine off and then snug the screws up and fire it up. I tried while it was running and didn't get the same results and the motor started running crappy. I guess it throws the computer off when you mess with it while the motor's running.


Very good info.


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## lilbigtonka (Dec 30, 2008)

Good info for sure but want we just idle it up like the manual says I think there is a idle adjustment also


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## filthyredneck (Feb 10, 2010)

Its a little harder to do by the manual lol, more stuff had to be taken off. This way, I only have to remove the right side plastic and loosen two screws on the tps. Not saying it's the right way to do things, but it works. And it's been like this since before mudstock last year and hasn't hurt anything so far.


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## wyo58 (May 13, 2011)

I guess the question still remains, why would the voltage regulator replacement cause a low idle? I would check your voltage output before I started messing with anything else. I would want to know why it happened. If the TPS is faulty then so be it.


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## kawi27 (May 19, 2010)

ya how many volts should the voltage regulater be putting out cause once i go in three feet of water and get out my bike wont idle i let off the gas slowly than it dies but it runs like a charm other wise. and when the bike is cool it idles fine


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## kawi27 (May 19, 2010)

and when i tried ightening up my throttle cable and it worked frine just a little choppy when it idled cause every time i started it the idle was either a little to high or perfect


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## wyo58 (May 13, 2011)

Running what kind of voltage do you have at the battery?


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## kawi27 (May 19, 2010)

when its just at idle its twekve volts but oncw i idle it up it hits 16 volts an dthat s as high as my meter reads


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## wyo58 (May 13, 2011)

Wow I would think 16 volts is quite high. A fully charged battery is around 12.6 volts (no load). I believe that getting somewhere around 14 volts would be normal running and rpm. If that thing is really putting out 16 volts that would mess with the ECU and all of it's sensors I think. So it's possible that that much voltage is changing the calibration of the TPS and changing your idle. I'm more in tune with car computer systems and any variation high or low on them sends the PCM in a frazzle. The only other thing I can think of is the battery, is it in good shape? If it's not taking a charge well it is possible that the charging system is working overboard. But still 16 volts is way high!


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## kawi27 (May 19, 2010)

ya i put in a new battery a month ago so maybe it is the voltage regulator they put in


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## kawi27 (May 19, 2010)

like when it idles super super low and you let idle like that for two minutes than it idles back up to normal. than you burp the throttle and it will either die or idle super low for a while


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## wyo58 (May 13, 2011)

There is an idle by-pass or stepper motor that controls idle for all conditions. Like if it's cold out the stepper motor (idle by-pass) adjust accordingly. As it warms up the stepper motor backs way out. So if it's getting some strange voltages it's gonna do strange things. Make sure your volt meter is reading correctly though before blaming the voltage regulator completely. Try it on even your car/truck, you should be getting roughly the same voltages as i described earlier.


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