Tuned 998 idle AFR?

[Turboflash]

I just installed an AEM AFR gage on a Stage 3 TCat. What should the hot idle AFR be?
When first started, the gage comes on line at 13.7. As it continues to run the AFR goes up and up and up until it goes out of range high side. The sled runs perfect in the test field beside my shop. It always has been a strong sled so I know the tune is good. Thanks!

 

[NYTurbo]

Phone your tuner

 

[Fleecer]

That's normal IMO, as my sled does the same, and my tune is from a different vender. Running low AFRs at 1/16 throttle is a waste of fuel IMO. They run lean up to 5-6000 rpm, and letting off the throttle in any range will permit numbers to climb as you state, but once throttle is applied again it should/will came back down within the spec.

 

[Turboflash]

Something is wrong because w this sled, it never comes back into range until I shut it off and let it cool a bit, then when re-started, it will be back in range but only like for a minute. AFR slowly climbs until its,out of scale again.
I think maybe sensor is bad. It's a Bosch LSU 4.9.

 

[sideshowBob]

I have had AEM system on my SW for over two years and have never seen the AFRs act like this with any tune or muffler combinations.

 

[max rolph]

change your wide band sensor, it should be anywhere from high 13's tho high 14's all in the no load cruising range or idle

 

[KnappAttack]

I typically see low to mid 13's at idle most all the time. I've never seen it that lean idling even.

 

[Fleecer]

Something is wrong because w this sled, it never comes back into range until I shut it off and let it cool a bit, then when re-started, it will be back in range but only like for a minute. AFR slowly climbs until its,out of scale again.
I think maybe sensor is bad. It's a Bosch LSU 4.9.

Oh....I thought it came into range once applying throttle! To continue climbing is not right.

 

[Srxspec]

It's either your sensor or it's the power wire that is powering the gauge if you wired it in. Make sure your power source is a constant 12 volts no matter the rpm or the gauge will act just as you describe.

 

[Turboflash]

Sensor was bad.

 

[max rolph]

knew it.

 

[jonlafon1]

That's normal IMO, as my sled does the same, and my tune is from a different vender. Running low AFRs at 1/16 throttle is a waste of fuel IMO. They run lean up to 5-6000 rpm, and letting off the throttle in any range will permit numbers to climb as you state, but once throttle is applied again it should/will came back down within the spec.

Your running TD tunes? What you seeing for AFR idle?
Thanks

 

[Fleecer]

knew it.

At idle......12.4. Give it a smidge of throttle, goes up to 13.7. This is no load, idling in garage.

 

[jonlafon1]

At idle......12.4. Give it a smidge of throttle, goes up to 13.7. This is no load, idling in garage.

Okay thanks.. Time for a fuel pressure test.. I'm idling pretty rich, guessing I might have a newer pump like justinator was posting about. I'm in the mid to upper 11's on a new motor..

 

[Fleecer]

I think you are gonna be fine. This can fluctuate depending on engine/outside temp, Tune/FP settings etc. If I let it idle long enough, it will drop into the 11's.