newbb
Extreme
Been trying to figure this HIGH idle issue my sled has for about a week now.
08 MTX
1.) The ISC(Idle Speed Controller) on mine was bad(stuck all way out) so I replaced it with a confirmed working one. No change in idle which I find very strange considering my old one was bad.
2.) No leaks or obstructions in airbox or intake boots. And no exhaust leaks.
3.) Throttle cable has been adjusted so there is a little slack in it up at the throttle so cable is not tight.
4.) Ran diagnostic mode to check TPS. In mode 01
- Throttle at fully closed gives a reading of 20
- Throttle at full Open gives a reading of 96
I checked the diagnostics sheet thats up on this site and it says the TPS number at throttle fully CLOSED should be 15-18. Could the fact that mine is at 20 be the reason for high idle? How is this TPS number adjusted?
Do I have to reset my CDI / ECU after new ISC is installed??
Is there a right way and wrong way to install the ISC? It just moves in and out so I wouldn't think so but figured I would ask.
Anyone have any other ideas of what can cause a High Idle issue?
Thanks and any help is much appreciated.
08 MTX
1.) The ISC(Idle Speed Controller) on mine was bad(stuck all way out) so I replaced it with a confirmed working one. No change in idle which I find very strange considering my old one was bad.
2.) No leaks or obstructions in airbox or intake boots. And no exhaust leaks.
3.) Throttle cable has been adjusted so there is a little slack in it up at the throttle so cable is not tight.
4.) Ran diagnostic mode to check TPS. In mode 01
- Throttle at fully closed gives a reading of 20
- Throttle at full Open gives a reading of 96
I checked the diagnostics sheet thats up on this site and it says the TPS number at throttle fully CLOSED should be 15-18. Could the fact that mine is at 20 be the reason for high idle? How is this TPS number adjusted?
Do I have to reset my CDI / ECU after new ISC is installed??
Is there a right way and wrong way to install the ISC? It just moves in and out so I wouldn't think so but figured I would ask.
Anyone have any other ideas of what can cause a High Idle issue?
Thanks and any help is much appreciated.
grizztracks
Tech Advisor
- Joined
- Feb 24, 2005
- Messages
- 3,112
- Age
- 60
- Location
- Scio, NY
- Country
- USA
- Snowmobile
- FX Nytro RTX, RS Vector, SR Viper RTX SE
The manual says to never remove the ISC and Yamaha does not sell it separately so there must be a reason for that. Does the new ISC vibrate when activated or does it act different in any way from the original. The throttle position sensor will read higher if the throttle is not returning to idle. I believe the TPS is for the throttle override system but I'm not sure if it ties back to the ISC. I guess it wouldn't hurt to check it and reset the angle if needed. You may also want to try syncing the throttle bodies.
- Joined
- Nov 1, 2009
- Messages
- 3,564
- Location
- Winnipeg, Manitoba
- Country
- Canada
- Snowmobile
- 2009 Phazer RTX
Is the idle screw just turned in too much? When did the problem happen?
canoehead
TY 4 Stroke God
- Joined
- Jan 14, 2011
- Messages
- 2,134
- Location
- NE, Alberta
- Country
- Canada
- Snowmobile
- 2014 XF9000, 2016 Viper XTX
Is there a fuel manager/programmer on it?
newbb
Extreme
The OLD ISC unit was just stuck all the way out fully extended and I tested it when removed and would not move in or out. The new ISC unit did move both ways when I tested it.
Anyone know why the ISC should NOT be removed? Too late now since I did remove it but wondering what the reason is?
Anyone else ever replace this ISC and get the sled to idle normal again?
How do I adjust the TPS sensor angle? Where is it located?
Where is the idle screw on this sled? I have not touched it myself. Sled idled high when I bout it.
No fuel programmer on it
thanks
Anyone know why the ISC should NOT be removed? Too late now since I did remove it but wondering what the reason is?
Anyone else ever replace this ISC and get the sled to idle normal again?
How do I adjust the TPS sensor angle? Where is it located?
Where is the idle screw on this sled? I have not touched it myself. Sled idled high when I bout it.
No fuel programmer on it
thanks
Under norm operation the iac will open up when the tps is above its known or learned closed throttle position voltage. If the iac didn't open up and the throttle is closed from lets say a full throttle opening the engine would probably stall from the lack of air. So if 20 is not the known closed throttle position for the ecu it thinks the throttle is opened and has opened the iac allowing more idle airflow causing the high Idle. Btw whats your location?
newbb
Extreme
How can I get that TPS number back into the 15-18 range?
I updated my profile location.
I updated my profile location.
the tps can be adjusted to lower the closed throttle number.
grizztracks
Tech Advisor
- Joined
- Feb 24, 2005
- Messages
- 3,112
- Age
- 60
- Location
- Scio, NY
- Country
- USA
- Snowmobile
- FX Nytro RTX, RS Vector, SR Viper RTX SE
newbb
Extreme
Thank you for the info.
Looks like I need to remove the throttle bodies from the motor to access the TPS sensor. Sorta tight up near the metal frame of the sled. Also looks like the two screws that hold it on are special star tool.....which I dont have. Ugh
Looks like I need to remove the throttle bodies from the motor to access the TPS sensor. Sorta tight up near the metal frame of the sled. Also looks like the two screws that hold it on are special star tool.....which I dont have. Ugh
newbb
Extreme
What could have caused my sled to show the 20 number at closed? if its suppose to be at 16 with the throttle closed, what could have moved to make the number jump to 20?
On the TPS sensor itsself I see a white line drawn from the throttle bodies across onto the sensor. I assume this is from factory. The line matches up still so it was not moved.....at least since the line was drawn.
On the TPS sensor itsself I see a white line drawn from the throttle bodies across onto the sensor. I assume this is from factory. The line matches up still so it was not moved.....at least since the line was drawn.
canoehead
TY 4 Stroke God
- Joined
- Jan 14, 2011
- Messages
- 2,134
- Location
- NE, Alberta
- Country
- Canada
- Snowmobile
- 2014 XF9000, 2016 Viper XTX
Someone said they just drilled a hole through the Delta box and used a bolt & nut to fill it after adjusting the tps . Torx set can be bought cheap, and you will probably need them down the road.newbb said:
grizztracks
Tech Advisor
- Joined
- Feb 24, 2005
- Messages
- 3,112
- Age
- 60
- Location
- Scio, NY
- Country
- USA
- Snowmobile
- FX Nytro RTX, RS Vector, SR Viper RTX SE
Does the torx screws have the nipple in the center which requires a tamper proof bit? I thought my Vector had the tamper proof torx screws. You'll need to skin the two wires to make the voltage reading to follow the procedure without a sub-harness. I would try slightly turning it in one direction then run the diagnostics on the TPS to see if it changed. I would also sync the throttle bodies.
nitris223
TY 4 Stroke Junkie
- Joined
- Nov 18, 2012
- Messages
- 589
- Location
- Yorkton Saskatchewan
- Country
- Canada
- Snowmobile
- Yamaha Nytro MTX
I still think there is something up with your throttle cable. I am pretty sure you can raise and lower the idle a bit with adjustments. We had a high idle issue while riding and it was the cable causing it. Yours may be different problem all the same. Might be good to pull the airbox and see if anything is going on there with one of the intake boots or even the throttle body . Maybe it is getting more air from some crack or something. Seems strange that the ISC didn't cure it. Yamaha says not to remove it but I see no problems with it. Unless they set them on a bench with a matching ECU but that is very unlikely because then you would not be able to buy a ecu if yours fried without knowing the parameters of the ISC. They could sell the part if they wanted to but instead they want to soak you for $1000 for throttle bodies and tell you it is not a replaceable part.
They tried selling me a fuel pump for a Rage one time, they don't have rebuild kits. Sled would not get any fuel to the carbs no matter how long you cranked it. They said the fuel pumps are bad and $400 would fix it. . I said there is no way 2 fuel pumps fail at the exact same time. Turns out they were air locked. Filled the float bowls with a syringe and then they would pull fuel.
They tried selling me a fuel pump for a Rage one time, they don't have rebuild kits. Sled would not get any fuel to the carbs no matter how long you cranked it. They said the fuel pumps are bad and $400 would fix it. . I said there is no way 2 fuel pumps fail at the exact same time. Turns out they were air locked. Filled the float bowls with a syringe and then they would pull fuel.
Pstn head
TY 4 Stroke Master
This is a long shot, you say you bought the sled used and that the old ISC didn't cycle properly in and out. Is it possible the previous sled owner adjusted the idle screw due to the ISC not working properly for it to idle? Now that you installed a new ISC the idle screw should be adjusted to achieve proper idle speed? Or if it even has an idle screw ?
