nytro running on two cylinders

[08nytromtxa]

the nytro runs fine all day put it in the trailer start it up in morning starts fine for about 20 to 30 seconds then cuts into two cylinders idling. i took stab in dark as i could only get to 1 plug without taking seat gas tank turbo etc.... off. turns out it started right back up ran perfect all day parked it in trailer put the heat on thawed it out. came home to pull it in shop and it did the exact same thing.... my thoughts is weak coils anyone had this problem?

 

[08nytromtxa]

i should also add i started it once it did this.. then unloaded other snowmobiles in trailer and about 20 minutes later it started up fine again but only for the same amount of time...

 

[redneckboost]

Coils

I have seen it before and was coils. Make sure connections are dry and making good contact. And i woild change plugs as well. Just my .02$. Or other electrical connections wet

 

[08nytromtxa]

I have seen it before and was coils. Make sure connections are dry and making good contact. And i woild change plugs as well. Just my .02$. Or other electrical connections wet

changed coil it is fine it ran good again this morning but i topped up fluids cleaned it up and it started up fine then went back to two cylinders... i looked in a little deeper and it was pissing fuel out the exhaust on that 1 cylinder... almost like a injector stuck wide open maybe.

 

[Thistledoo]

if a injector sticks she will fllood Id think.

disconnect the secondary injectors and eliminate that. Usually they stick wide open or close completly. But make sure one isnt dribbling.

 

[08nytromtxa]

if a injector sticks she will fllood Id think.

disconnect the secondary injectors and eliminate that. Usually they stick wide open or close completly. But make sure one isnt dribbling.

yes was just going to head back after lunch to eliminate the extra set to see if it got better.. if the two wires to my number 3 coil in my stock wiring harness rubbed together and grounded i think it would stick that injector wide open right?

 

[Thistledoo]

I dont think your gonna have wiring issues if the sled ran all day and just farts around here and there. Just use a pair of needle nose vise grips and pinch off the fuel line going to the intercooler. U can go for a short ride and she how it runs and if it cleans up. Extra fuel isnt needed until like 5 psi anyhow.

 

[08nytromtxa]

I dont think your gonna have wiring issues if the sled ran all day and just farts around here and there. Just use a pair of needle nose vise grips and pinch off the fuel line going to the intercooler. U can go for a short ride and she how it runs and if it cleans up. Extra fuel isnt needed until like 5 psi anyhow.

it has to be something simple went out it started fine drove it around it runs flawless weather or not i unplug the extra set of injectors.. throughout the afternoon i started it several times now, and it runs and idles like it should. in the morning it could be a whole different story. the boost it box is working perfectly my air fuel is dead on wide open. seems like all the weird uncommon stuff always has to happen to me!!!!

 

[Thistledoo]

your not running the mcx box?

if a injector is dribbling when its cold it wont help to unplug the box....you have to kill the fuel source

 

[autopro]

2 cylinder nytro

I would look at the ignition system. If you loose spark in a cylinder it will pump the unburned fuel into the exhaust. Try swapping ignition coils from the suspect cylinder to another and see if the missfire follows.
Autopro

 

[08nytromtxa]

your not running the mcx box?

if a injector is dribbling when its cold it wont help to unplug the box....you have to kill the fuel source

I am running boost it if I unplug the box it shuts off all power to the injectors and mine is not a dribble it is like a full throttle spray by the looks of it

 

[08nytromtxa]

I would look at the ignition system. If you loose spark in a cylinder it will pump the unburned fuel into the exhaust. Try swapping ignition coils from the suspect cylinder to another and see if the missfire follows.
Autopro

Yes I tried swapping coils out with good ones from a different yamaha and it makes no difference. I pretty much know it has to be a injector by the amount of fuel that sprays out of exhaust

 

[08nytromtxa]

well now i cant get it to run on two cylinders at all. musty have been wet connection somewhere... i am sure it will happen when i least want it to ha ha.

 

[martin_e_wilson]

unplug injector that is poring fuel if it stops poring fuel injector isn't stuck its electrical, should start on 2 cylinders