Throttle Position Sensor (Make some MOney?)

[chasineyes]

Does anyone have any experience with setting the "volts" on the TPS on a Polaris Sportsman 700 EFI? We have one that runs/idles great but under load it goes into a limp type mode. In the past we had some battery issues and discovered some folks were jumping it off a truck battery. I have a feeling we have have toasted the sensor OR threw the volt regulation out of wack. I have read that there is a certain amount of volts that need to be present on this for it to work correctly. Any thoughts?

[NAMASafetyDirector]

There are parameters and specific ohm readings for the TPS sensor at closed throttle and at WOT. The TPS is set from the factory and has a tamper proof screw in most cases. You should NOT attempt to adjust the TPS unless you have the correct values and an accurate way to monitor. I would say that is probably not your issue if the machine seems to fire up and idle correctly as the TPS works in unison with the ECU as soon as the engine tries to start. If the TPS is off at all, you will experience poor starting, poor idle or no starting at all since the ECU will be getting the wrong info from the TPS right away which will have the fuel delievery/mixture and the timing screwed up. I would work with the TPS as a last resort. It could definitly be bad but is on the "more than likely not" list to start with. Those ohm readings should be available if not, let me know what year machine you have and i can try find out for you.

[NAMASafetyDirector]

It appears unless i missed something that the voltage reading (not ohms in this case) should be 5V at WOT for the TPS. This was for a late model 700 EFI.

[NAMASafetyDirector]

My only other suggestions would be to check fuel pressure (should be in the neighborhood of 40-43 psi). Additionally, I would check the throttle cable adjustment in relation to the ETC on the throttle assembly (throttle block on the handlebar). Sometimes if the cable gets way out of adjustment the contact on the ETC (Electric Throttle Control)pivot gets out of whack and doesnt work as intended and the machine will go into a limp as in a stuck throttle situation. Good Luck and let me know if I can help any further...

[rundrave]

the TPS can be adjusted just above the throttle assembly. there should be a piece of rubber you can roll back on the throttle cable and make adjustments there to keep the contacts in the throttle housing from touching which then kills the machine.

[NAMASafetyDirector]

That would be the ETC. The TPS cannot be manipulated unless you either adjust the cable so much that it begins to open the butterfly at which point the ETC will show that the throttle is open, but the engine is not running and it will either not start or be in limp mode right away. The only other way to adjust the TPS is to loosen the tamper-proof (or at least it should be) screw that holds it in place.

One last thing that comes to mind is to remove the throttle body and give it a good cleaning. Over time, oil, deposits and gunk can build up that may keep the butterfly from closing all the way or at the very least make it stick and cause issues.

[rundrave]

you are correct, I should have worded my post to say to check the ETC also and see if it is adjusted correctly.

sorry for the confusion.

[chasineyes]

Hey guys thanks for the tips. I took intake manifold off and gave it a good cleaning. I also changed the plugs (noticed one had the tip broke!). It is STILL "retarding" above 10MPH or 3000RPMs. I did check fuel pressure and with a "tire gauge" I was getting 38-39PSI. I spec'd that on the polaris site and they were calling out 40PSI +/- 3PSI. So I don't think that is the problem.

WHAT dawned on me tonight out fishing is I wonder if the reverse override switch might be bad. The machine is acting just like when you try to back up and go too fast. Fortunately I have the machine down to the bare bones so getting to stuff is quite easy, just don't know exactly what I"m looking for....YET!

[NAMASafetyDirector]

Did you even get that thing figured out? Am curious to know what it ultimately was.

[chasineyes]

So we took it to the shop and they found out that under load it wasn't getting enough fuel. They then wanted $580 to install a new pump/fuel tank kit. I said hell no, and brought it back home. That afternoon I removed the fuel pump and found that the intake filter was extremely "dirty/foul/nasty". After removing that I took a look at the bottom metal screen of the pump and that was "plugged" as well. So after some cleaning (I didn't put the intake filter back on yet) it is running JUST FINE!!! So maybe I dodged a bullet. Now I just need to spend that money on 2 new front tires, then off to for sale market!!!

[NAMASafetyDirector]

Wow, ok well glad you got it figured out! My Uncle always used to tell me...."Never overlook the obvious"! HA! Good luck!