[C2GCPVA]

Sportsman 2016 450 H.O. EFI will idle for about a minute then idle goes lower and shuts off. ATV only has 71 hours. Its worse after the engine warms up. It came in barely running & had been sitting for awhile so drained the gas, changed the spark plug, and changed the injector it seems to run fine now just wont stay idling like before, especially once warmed up. I scoped the crank sensor and it looked ok, I also scoped the voltage going to the coil and it was dropping out every so often so I changed the coil and the voltage stopped dropping out but still wont idle. I'm thinking about changing the crank sensor now but was wondering if anyone has ever run into this problem / knows of any common issues I'm overlooking.

 

[Mech]

Does it have an O2 sensor ? That controls idle mixture. and only after it's warmed up.

Have you checked the sparkplug after it's died to see if it's rich or lean ?

 

[Johnson31]

Sportsman 2016 450 H.O. EFI will idle for about a minute then idle goes lower and shuts off. ATV only has 71 hours. Its worse after the engine warms up. It came in barely running & had been sitting for awhile so drained the gas, changed the spark plug, and changed the injector it seems to run fine now just wont stay idling like before, especially once warmed up. I scoped the crank sensor and it looked ok, I also scoped the voltage going to the coil and it was dropping out every so often so I changed the coil and the voltage stopped dropping out but still wont idle. I'm thinking about changing the crank sensor now but was wondering if anyone has ever run into this problem / knows of any common issues I'm overlooking.

I am having the same issue with a 2016 Superman’s 450 with 41 miles. What was your solution?

 

[Mech]

The temp sensor would be a suspect for those symptoms..

 

[Johnson31]

The temp sensor would be a suspect for those symptoms..

Could temp sensor mess up without causing a light on the screen? It has a emblem for temp but it’s not lite up

 

[Mech]

I think you will find there are two temp sensors, one for the fan and light, and another for the engine management. The engine management sensor will be the suspect one. If the computer thinks the engine is running cooler than it is it will enrichen the fuel more than it should.

If the temp sensor for the efi got a broken wire then I think the engine light would light up, but if the temp sensor is out of range but still connected, the efi doesn't detect that as a problem and doesn't turn the engine light on. Most of the sensors on older/simpler efi systems work like that. More modern systems deduce there is a problem by monitoring the temp against time after a cold start, and if it doesn't start off with the expected temp, and then change it's reading by the right amount after a certain time then the efi deduces thee is a problem. I don't think the software in a polaris is that sophisticated though.