I really hope someone can help. My atv will sometimes die at idle but will always start back up. But a few weeks ago while riding the rpm's went crazy high while driving. I put it in park and then just started climbing on thee own all the way up to 3800. I shut the key off started it back up and drove fine for 30 minutes.




Been at the dealer for 4 weeks now. They have tried new battery( Polaris computer said it had dead cells) TPS sensor, new spark plug, check for broken wire no luck.


Today he said he is trying IAC and hopes that its.


Really frustrated that he cant fix it. Any ideas what it could be?




Rick

 

Just guessing though the main problem we had was on the thin wiring and cheap connectors not the sensors themselves. Even the manuals say that efi problem are 85% wiring related not the modules. Tbap wiring and connector can do this along with the tps wiring and connector. All it takes is a small bare wire or a soft feeling wire that has melted internally to cause problems. Read the "sticky" post section above this one on "Spilling the beans on 700 efi problems". Relates also to the 500 and all efi atvs.End result of this post is that a member started making stronger harness repair kits.https://otbpowersports.com/products/

 

Thanks for getting back to me. So how do you find that one bad wire?

 

Some breaks in wiring are clearly visible,some just feel soft in spots that have melted. Plus on some the connector pins can pull back and not make good contact. On some I was able to wiggle the tbap wiring harness and noticeably change the engine idle. Plus another item that people over look is the rubber grommet that holds the tbap into the intake manifold can split and suck air and cause problems(item#9). You can check this out also.Another place to check is the crank position sensor harness that runs under the intake manifold. All it takes is a bare wire contacting the starter or engine.

 

ill check you have been a big help ill let you know how it turns out

 

Just got off the phone with him. He said he check the wires and ran test with Polaris through his computer and said everything checked out.


I hope it is the IAC .......this trial and error is really getting expensive. BTW on top of that when he tried running the test with Polaris they said my battery was week and in order to run the test properly they had to install a new battery ($110)
I didn't know you could run test with the computer and polarais to see if there was a broken wire

 

That's the thing on wiring faults. Digital Wrench can't always find them plus they may or may not throw codes on your speedo or on the software. Hope what they're doing solves the problem.

 

me to ill keep you posted they should be installing the IAC right now

 

I was wondering to being 10 years old maybe a grommet dried out? or rubber connector?

 

The tbap grommet was one of the things I said to check as I've found them split in half before causing erratic idle.Just remove the holding bolt and wiggle the sensor out. Grommet will usually stay on the sensor.