TPS Switch/Sensor question

[stoutner]

Does anyone have their nitrous hooked up to activate from their TPS switch?

I am trying to set mine up to do so but am not getting a "good" reading from my TPS sensor. I have been told that the sensor has 3 wires.

one is constant 5 volts dc

the second is ground and may read .0 - .5 volts dc from feed back

the third is your signal wire. I have been told that it should read .5 volts at idle and 4.6 volts at full throttle.

I tested it with the key on and sled not running. I am getting the 5v dc and the ground wire reads .0 at idle and .5 at full throtttle.

the signal wire (Yellow Wire) however reads only .5 at idle and 3.6 volts at full throttle. When i hook it into my boondocker controller, the output voltage drops to 2.3 v dc at full throttle.

Can someone let me know if theirs is the same? If the light pod is off, you can check the dc voltage where the yellow wire goes into the wire harness.

Any help would be appreciated.

 

[Len Todd]

Sounds like your TPS may not be adjusted correctly. Darn Tech Manual has you setting the TPS using a 4.5 VDC external source (Versus 5 VDC) and does not refer to a WOT setting. But, .. with a 4.5 VDC source, the idle is set at .136 VDC, which is quite a ways from .5 VDC. Have you had the TPS off or adjusted it? Before I moved it, I would try to figure out the reason for this delta. I had one go bad once on one of my Arctic Cat "fuelies." All kinds of weird things happened when it did.

At any rate, when you tie into the other circuit, it is loading the TPS's circuit. I would imagine that you would have to readjust the TPS after tying into that second circuit. If there is not enough adjustment, you would have to figure out a way of buffering the TPS circuit from the second circuit. Possibly a high value resister in series with the second circuit would do the trick. I do that with audio circuits and it works well.

Good luck finding someone who has done what you are proposing. But, I am sure someone out there has done this.

 

[stoutner]

Sounds like your TPS may not be adjusted correctly. Darn Tech Manual has you setting the TPS using a 4.5 VDC external source (Versus 5 VDC) and does not refer to a WOT setting. But, .. with a 4.5 VDC source, the idle is set at .136 VDC, which is quite a ways from .5 VDC. Have you had the TPS off or adjusted it? Before I moved it, I would try to figure out the reason for this delta. I had one go bad once on one of my Arctic Cat "fuelies." All kinds of weird things happened when it did.

At any rate, when you tie into the other circuit, it is loading the TPS's circuit. I would imagine that you would have to readjust the TPS after tying into that second circuit. If there is not enough adjustment, you would have to figure out a way of buffering the TPS circuit from the second circuit. Possibly a high value resister in series with the second circuit would do the trick. I do that with audio circuits and it works well.

Good luck finding someone who has done what you are proposing. But, I am sure someone out there has done this.

I took it out of the "external" circuit and I got .62 vdc at idle and 3.6 vdc at full throttle. I did adjust It so that I got .68 at Idle and 4.0 at full throttle.

Even at max adjustment, I could only get 4.3 vdc at full throttle.

The problem with the voltage drop turned out to be a fualty wire crimp. It is resolved now...thank god.

 

[kinger]

Un related to your question of using the factory TPS but I have a hard mounted TPS switch on the throttle linkage so its mechanically tripped with the arm rocks all the way to WOT.

This year i am bypassing that in favor of a button but I have two spade connecters and can go back and forth easily to see which I like.

If your interested in the mechanical TPS switch I can shoot some pictures for you, the carbs are off teh sled right now.

 

[Len Todd]

Looks like we got someone talking to you now.
Was your final WOT setting with the gas circuit connected? May want to consider the resister. Also, you may want to consider soldiering the crimped connection. Low voltage circuits are very sensitive to bad connections.

 

[87gtNOS]

I run the ZEX nitrous switch. It learns your TPS voltage.

I think it's the yellow wire you need to use on the TPS.

I even had mine all apart just lately and when hooked all back up, it never forgot what WOT was!!

 

[87gtNOS]

the signal wire (Yellow Wire) however reads only .5 at idle and 3.6 volts at full throttle. When i hook it into my boondocker controller, the output voltage drops to 2.3 v dc at full throttle.

go into diagnostic, then select the TPS setting...should be 16 or 17 at closed throttle...I think.

Regardless of the output the ZEX will learn this. If you are loosing output when the accessories are turned on, then that's because the sled is not running and they are taking their toll on your battery.

Another thought...stone (Ernie) is having battery troubles...I wonder if the summer tar racing is taking it's toll on your batteries? Starting the sled and only running it for 40 seconds at a time might be hard on it!!

 

[87gtNOS]

The problem with the voltage drop turned out to be a fualty wire crimp. It is resolved now...thank god.

Ooops, just saw this!!

I will grab the manual outta my truck in an hour and tell you the specs for the TPS.

 

[87gtNOS]

In diagnostic mode....mode 01.
readings are 15 to 18 throttle closed
and 95 to 100 at WOT.


Then TPS closed voltage should be 0.63v to 0.73v between yellow and black/blue.

 

[stoutner]

Kinger, Thanks...but I will stick with the Factory TPS.

Len, I did test it with everything hooked up. I did finally get a good reading once I solved the bad connection.

Jonathan, Thanks for the info. Mine is a Boondocker controller. After I found the bad wire crimp in the controller harness, I tested it and am getting 4.0 volts at WOT and no voltage drop with everything including the controller hooked up.

Unfortunately, after a few calls to Boondocker for some further troubleshooting, It was determined that I have a bad internal connection in my controller. My controller is supposed to read about 20 at idle and about 200 at full throttle (5.0 vdc). Unfortunately, it reads 15 and doesn't react at all when I give it throttle.

Luckily, Boondocker has been very good to me and will be repairing asap at no charge. It is still under warranty.

My only question is...What is the function of the TPS on a stock sled? Does it tell the ECU to add fuel based on throttle position? Or, is it just a safety device?

 

[87gtNOS]

My only question is...What is the function of the TPS on a stock sled? Does it tell the ECU to add fuel based on throttle position? Or, is it just a safety device?

adds fuel, and I don't think it has anything to do with timing as I think the timing is control by the crank sensor.

Throttle position may help the ECU determine loads too based on rpm, etc...

 

[stoutner]

Well,

If it adds fuel, I did adjust it up slightly. Will my sled run richer now?

 

[87gtNOS]

Well,

If it adds fuel, I did adjust it up slightly. Will my sled run richer now?

You'll be fine.