High Revs On Start Up

[MrPython]

I've got a '01 955i Sprint ST with only 25k miles on it. It's been running great and all of a sudden when I start it the motor rev's really high. So high I have to shut it down. I've looked online and seen some guys talking about the two-stage idle motor or the Throttle position sensor. I checked the two-stage idle motor and it goes up and down when I turn the key on so I'm guessing it's the TPS. Any help on this would be greatly appreciated.

 

[shanered6]

I will assume you have checked your throttle cable for wear or kinks in the cable and that it is sitting in its saddles correctly , so if and its the TPS then you need to replace it as they ether work or dont .
They can go out of position some times if the screw comes loose but its not common , the other thing to look for is if there are any of the vacuum pipes have any splits in them or maybe come off . Good luck let us know how you get on .

 

[MrPython]

I will assume you have checked your throttle cable for wear or kinks in the cable and that it is sitting in its saddles correctly , so if and its the TPS then you need to replace it as they ether work or dont .
They can go out of position some times if the screw comes loose but its not common , the other thing to look for is if there are any of the vacuum pipes have any splits in them or maybe come off . Good luck let us know how you get on .

Thanks for your reply. Yes, I've checked the cable. It has a full range of motion and works as it should. I checked the hoses and didn't find any that were bad. I did replace some that were ify. I replaced the TPS and it still does the same thing. I haven't had a single problem with the bike and then all of a sudden this happens. Is there a diagnostic program I can get for free to use through the OBD port?

 

[shanered6]

Try disconecting the battery over night and see if that makes any differance , and check your rubber manifolds for cracks as well it could be sucking air somewere ?
It could be fuel starvation as well has the fuel filter been changed .

 

[MrPython]

Try disconecting the battery over night and see if that makes any differance , and check your rubber manifolds for cracks as well it could be sucking air somewere ?
It could be fuel starvation as well has the fuel filter been changed .

The battery has gone dead after this started. Fuel starvation I don't see that as the problem. When it starts it's got more than enough gas to rev 8g. But I did need to use starting fluid the last time. I can't see the fuel filter causing this. A clogged filter would be starving the motor not revving it higher without turning the throttle. I used the app torque pro and it showed the throttle position at 23.41 with the motor off and it shows the same after I changed the TPS.

 

[MrPython]

I've got a '01 955i Sprint ST with only 25k miles on it. It's been running great and all of a sudden when I start it the motor rev's really high. So high I have to shut it down. I've looked online and seen some guys talking about the two-stage idle motor or the Throttle position sensor. I checked the two-stage idle motor and it goes up and down when I turn the key on so I'm guessing it's the TPS. Any help on this would be greatly appreciated.

Update for anyone who cares. After changing the TPS and still having the same problem I did a very close-up as in inch by inch check of the cable. Low and behold the previous owner had a problem and instead of buying a new cable he tried to put a bandaid on this one and hide it with some shrink tubing. All that effort to hide it instead of just putting a new one on. I don't get his thinking and the waste of time but it's back to normal. Thanks to those who tossed out your suggestions and were right on the money.

 

[sikatri]

Hindsight 20/20, followed this thread with interest, would have been perhaps helpful with more background and history on the motorcycle. When I read the first OP and it said its been running great and all of a sudden. I assumed you were a long time owner of this motorcycle. Now I’m not sure how long you’ve had it. I’d bet there might have been a few more responses not necessarily the right ones, but going over all the cables might have come up. When I bought my Thruxton used it too ran great at first. LoL. Then all the neglected or worn electrical components started to pop up. Glad you got it running!

 

[sikatri]

PS a picture of the cable would be interesting..

 

[MrPython]

Hindsight 20/20, followed this thread with interest, would have been perhaps helpful with more background and history on the motorcycle. When I read the first OP and it said its been running great and all of a sudden. I assumed you were a long time owner of this motorcycle. Now I’m not sure how long you’ve had it. I’d bet there might have been a few more responses not necessarily the right ones, but going over all the cables might have come up. When I bought my Thruxton used it too ran great at first. LoL. Then all the neglected or worn electrical components started to pop up. Glad you got it running!

PS a picture of the cable would be interesting..

 

[MrPython]

When I got the bike it only had 25k miles on it. I've never had a cable go bad on any bike I've owned in the past 50+ years. Sure, I've stretched a few clutch cables doing burnouts repeatedly to where I had to adjust it so I could get home. lol. But a throttle cable going bad in the middle with no kinks or turns? Is that just bad material from the get-go or what? Maybe that's Karma telling me I don't need this bike anyway. I hate being forced to use a helmet when I've never liked them on the street. They pull my head back at high speed, they cover my ears, and take away part of my senses I need to be aware of what's around me without having to turn my head. Even the half helmets suck. Now my dirt bike I always use a helmet. Every time I take out one of them I end up breaking something usually me. lol. I sat on the side of a mountain for over 3 hours waiting for someone to come looking for me. I know they couldn't leave due to the fact we were in my truck and I had the keys in my pocket. lol. Just a broken arm that time. Something about a man's got to know his limitations. lol. So, I guess I'll have to be happy with driving my Corvette convertible if I want the wind in my hair. At least I've got tunes in the car. lol. You want to buy a bike?

 

[sikatri]

When I got the bike it only had 25k miles on it. I've never had a cable go bad on any bike I've owned in the past 50+ years. Sure, I've stretched a few clutch cables doing burnouts repeatedly to where I had to adjust it so I could get home. lol. But a throttle cable going bad in the middle with no kinks or turns? Is that just bad material from the get-go or what? Maybe that's Karma telling me I don't need this bike anyway. I hate being forced to use a helmet when I've never liked them on the street. They pull my head back at high speed, they cover my ears, and take away part of my senses I need to be aware of what's around me without having to turn my head. Even the half helmets suck. Now my dirt bike I always use a helmet. Every time I take out one of them I end up breaking something usually me. lol. I sat on the side of a mountain for over 3 hours waiting for someone to come looking for me. I know they couldn't leave due to the fact we were in my truck and I had the keys in my pocket. lol. Just a broken arm that time. Something about a man's got to know his limitations. lol. So, I guess I'll have to be happy with driving my Corvette convertible if I want the wind in my hair. At least I've got tunes in the car. lol. You want to buy a bike?

Agree, a man’s got to know his limitations! LoL. Your motorcycle would be way too much for me. LoL.