Hello,, Ive been seaching everywhere to help my problem.

Now the bike stalls at idle, and and now it backfired a few times. Seems to run good at speed, I can take it around the block and seems to run fine.. but when let off the gas, stalls..

I have a 2006 Polaris Sportsman 500 EFI. Ive had a problem with it not running right. I took it to the dealership and they told me I needed a complete new wire harnass as well as the front computer module (the box at the handle bars area). After the replaced that for a VERY heafty amount, the also advised i needed a IAC valve. They said it would stall at an idle if not replaced it.

So, I could not afford their prices, lol, I orderd an original new part and it still stalls at an idle.

Ive checked the slack in the throttle cable, new fuel pump, new wire harness, module box, IAC valve...

Im Lost.

Thanks
Scott

 

Welcome! I never had to replace an IAC valve,tps sensor(couple times I had to when they were tampered with!,or a map/t-bap sensor) Sensor wiring harness shorts were the main problem!Dealer sounds like he just wants to replace parts! Backfiring,stalling at idle,but runs good at speed, is signs of a definite short in the wiring harness/ connector for the map sensor located on the intake manifold. I replaced a dozen or more of these kits just on the 500 alone! Rarely does the Grommet fail and suck air,but also can be a problem. Look at the "sticky" post section above this section on EFI problems,applies to all models,not just the 700 and 800 models! Stronger harness kits are available for your 500 on Ebay as I wouldn't recommend the Polaris replacement #2876315 map sensors harness repair kit!
The grommet is #3089902. You can pull the plate that holds the map sensor off and pull the sensor up to check the grommet. Replace the grommet if split. Here's where the sensor and grommet are located. http://www.cyclepartswarehouse.com/f...2006&fveh=7107 You can physically check also for any bare wires or soft feeling wires(internal breakage) from the sensor down into the main harness,plus see if any wires may have pulled out from the connector itself. The kits do come with a new connector and about 8 inches of wires to splice back in.On rare occasions the tps sensor harness can have shorts also,but usually doesn't run well at all if it does.Polaris harness repair kit # 2878498 (also available aftermarket with stronger wiring and connector on Ebay)
OPT

 

Hello, Thanks

I have the map sensor and the grommet on order and should be here next week..

When I took off the map sensor, the grommet came off with it. The rubber grommet was sloppy. I tried to take the grommet off the sensor very very gently, but it tore in half. Also inside the sensor was very dirty...

With all the problems Ive had with this bike, I'm not getting excited that this is the problem... but I'm keeping my fingers crossed.

Thanks

 

Replace the grommet by all means since it's split ,but the sensor itself can be wiped off and reused.If you still have a problem after you replace these two items check into the harness repair kits! Keep us updated. OPT

 

Hello,
My name is Anthony I am new to the forum. I am having the same exact problem with my 2006 Sportsman 500EFI.

It has all new wiring, tps, map w/grommet, IAC, Fuel pump, Fuel filter, stator, start components, spark plug, checked all battery cables and throttle cable adjustment and computer module at handle bars.

It is not throwing a code, I have unplugged different sensors to see if it would help, nothing m unable to reset old codes to verify not throwing hidden codes.

I am a bit lost now, any advise is appreciated.

Anthony

 

If you've done all that including replacing the map sensor harness kit and connector it probably would have been cheaper to have it hooked up to Polaris Digital Wrench to find the problem! Wiring problems are 85% of efi problems not sensors.This is from the manual. Most dealers charge 1 hr diagnostic fee and can save you a lot of frustration. I know,to a lot of people most dealers are akin to the devil himself,but at times especially on efi machines they can save you from replacing parts needlessly. Plus you can look at the "sticky" post above on 700/800 efi problems(pertain to the 500 also) If you have a map sensor harness problem you can check this out. Only The Best (the 500 kit is at the bottom right)

 

I have an appointment for tomorrow, so I will see what they say and will post the results. Thanks for the reply.

 

Well I took to Polaris. They could not find anything wrong.
Fuel pressure good, no codes on computer, they verified tps adjustment, checked all wiring.
Still does it, so will just use the way it is.

It is weird, sometimes it will run great, turn the key off and back on you have a 50-50 chance of running good.

 

I'd suspect an ignition switch intermittent problem if no codes were thrown and it's a "50/50" chance on start up every time you kill it and try to restart. That would be one of the things I'd at least swap out if I was still at the shop to see if I could eliminate the problem. Sometimes it can be something simple as this. Plus just pulling the flywheel cover and cleaning around the stator/flywheel area might help.If none if this helps I would still check for soft or bare wiring especially on the map sensor harness where it goes into the main harness.This is the most problem area we had to deal with at the shop. Map sensor repair kits kept us busy and can cause all sorts of problems from no start,intermittent idle. Plus as you said will run fine one time,bad the next or hard to start. Diagnostic equipment can't always pick this up or codes won't always show up on the speedo..

 

They change/check the ECM brain box. When those things take a brain fart lots of strange things will happen.
Even if it checks out ok it can go stupit a mile down the road.