Low Idle Afr Nytro

[chris_erhard]

I have a Yamaha nytro MPI supercharged with the gems controller, i am having an idle issue where AFR readings are as high as 22.4 … I have changed my low rpm Gems settings as high as possible and there is no change.

One thing that I have noticed is when I turn the key on, without starting the engine, my afr gauge boots up and displays 22.4. Is my Afr sensor going bad?

Sled runs good Afr numbers when revved up, Afr drops lower at mid rpm’s then and actually runs rich at higher rpm’s.

Sled tends to stumble off the line unless I feather the throttle.

I’m thinking it may be a vacuum leak but would the sled even run at all with Afr above 20??
Could my blow off valve be stuck closed at idle?

Thanks,
Here’s a video

 

[MrSled]

I would guess you have a bad sensor... boosted sleds when running any kind of race gas will take out sensors.

 

[Twintube]

Mine is doing the same thing. Replaced the sensor, same thing. Any luck?

 

[MrSled]

What gauge? You running HID?

 

[Twintube]

What gauge? You running HID?

Innovate gauges

 

[Twintube]

Innovate gauges

 

[MrSled]

Explain to me how yours is reacting.

 

[Twintube]

At first After start up gauge would read 22.4. Occasionally read 7.1. Replaced the wideband sensor with a bosch. Now reads 7.1 or so at start up. Give it throttle goes to 22.4. Pull the sensor out of the pipe and layed it then started the sled, same thin. Did the rag test by spraying brake cleaner on the rag and covering the sensor to read rich. Will read 7.1.

 

[Twintube]

Only thing different is the cold air pipe for the mpi s/c. And mbrp headers and muffler.

 

[MrSled]

Has this always been a problem or did this just start to happen?

 

[Twintube]

Has this always been a problem or did this just start to happen?

Just started last night.

 

[MrSled]

Just started last night.

Maybe try a different power source. AFR Sensors can be a real pain in the azz for after market wiring. I had HID interfere with them on start up and had to turn on gage after the sled was fired up.

 

[Twintube]

I do have LEDs in ir. Replaced one of the LEDs with a different brand. Ill have to look into that when i get home. Thanks for the info.

 

[Twintube]

If you think of anything else let me know.

 

[MrSled]

If you think of anything else let me know.

Will do.