Nytro,wont run fine

[AZOLSC]

The nytro will start right up when cold,will idle fine for a few minute,after a few minute it will start to missfire,If i touch the throttle it will either rev fine or stall.After arround 5minute of driving it wont idle at all and if i keep driving it for about 20minute backfire are alot worse and i wont be able to start it back until i wait arround 30minute to let the sled cool down.i've changed the 3 ignition coils with brand new one,new plug,new gas,new gas filter,bypassed tors.When it wont start and i keep cranking the engine for like 20-30 sec i have a fuel smell from the exaust.
Compression test was 205psi-210psi-215psi.Fuel pump is working,the only code im getting is 81 and 81 is for the grip warmer,tps show 16-96 on diag mode.Sled has also 33,720 killometer(21k miles)

I bough it in summer and i've only seen it running for like 30 second,seemed like it was running fine,but it wasnt the case,i couldnt test drive it back there was no snow and snowmobile are cheaper in the summer.Paid 3200$ cad for it i've been trying to fix it for the past 3month and i cant figure it out.I would appreciate some help from here thanks you

REPLACE THE BATTERY I HAVE HAD SO MANY ELECTRICAL ISSUSE WITH TEH BYTRO AND CODES STRIPPED THE SLED DOWN THEN I REPLACED BATTERY IT RAN FINE ITS THE MOSTS STUPIDEST THING EVER UR IF THE BATTERY IS OVER 6 MONTHS OLD HOLDS A CHARGE REPLACE IT YOULL BE SHOCKED

 

[Sno-Xr]

REPLACE THE BATTERY I HAVE HAD SO MANY ELECTRICAL ISSUSE WITH TEH BYTRO AND CODES STRIPPED THE SLED DOWN THEN I REPLACED BATTERY IT RAN FINE ITS THE MOSTS STUPIDEST THING EVER UR IF THE BATTERY IS OVER 6 MONTHS OLD HOLDS A CHARGE REPLACE IT YOULL BE SHOCKED

I think this is my next step. May try and rig up one of my known good Viper batteries....it sucks that the + - are reversed, but might be able to temp run it. Thanks

 

[Sno-Xr]

I think this is my next step. May try and rig up one of my known good Viper batteries....it sucks that the + - are reversed, but might be able to temp run it. Thanks

The only thing that has kept me from swapping batteries, is when the voltage drops, it drops to 12v measured at the battery. Which Id think would indicate that its loosing the extra charging voltage and not the actual 12v battery voltage

 

[AZOLSC]

The only thing that has kept me from swapping batteries, is when the voltage drops, it drops to 12v measured at the battery. Which Id think would indicate that its loosing the extra charging voltage and not the actual 12v battery voltage

Listen I have a electronic engineering degree I did every test on my nytro and the battery couldn't find the problem and then my buddy who has no idea what a screwdriver is said try a new battery prob only time I ever listened to him and sure as #*$&@ it ran perfect I can't explain it You know exactly what's going through your head there's no way can be the battery it's testing good it's holding a charge blah blah blah I know what's going through your head Cause I did the same thing replace the battery spend the 130 bucks and Then you can send me a thanks lol

 

[Sno-Xr]

Listen I have a electronic engineering degree I did every test on my nytro and the battery couldn't find the problem and then my buddy who has no idea what a screwdriver is said try a new battery prob only time I ever listened to him and sure as #*$&@ it ran perfect I can't explain it You know exactly what's going through your head there's no way can be the battery it's testing good it's holding a charge blah blah blah I know what's going through your head Cause I did the same thing replace the battery spend the 130 bucks and Then you can send me a thanks lol

Lol, i get it, believe me. We've checked tire pressure in a buddies car when it wouldnt start, and sure a #*$&@ the car stared!! I dont count anything out! Hahaha

 

[Anthonynytro]

Check the junction connector on the left side near the injectors, there's one with 3-4 red wires with a black end. Mine was corroded and it sounded like it was missfiring