ok my car has been tuned now for 4 years without a single problem until recently.. i dont know if it had anything to do with any new versions of smanager or something else.. i really need some insight i cannot seem to fix this.

here is the problem: while sitting and idling my air fuel stays steady around ~14.7....when cruising in closed loop on hwy the air fuel goes from 14.7 then jumps up to 16 or 17. it does this repeatedly back and fourth every couple seconds. you can feel it going down the road when it goes lean every 2 seconds and then back to 14.7

im using my bosch wideband sensor for the closed loop. dont think it has anything to do with the sensor because air fuel is steady at 14.7 when idling...it only does this when moving. im thinking maybe something to do with a new version of smanager and or soemthing in the tune??

thanks for any help

 

What are your min and max short term corrections?

 

hmm, look into inputs..

it could be a bad TPS potentiometer (or wireing). making your engine think its in decell

do you have the ability to log

 

i guess thats something in the new versions of smanager...but i never messed with it.. so it has the original settings in them still..

min short term is -30%
max is 47%

good or bad?

tps is working wonderfully.. i did do some datalogs and looked them over and didnt see anything out of the ordinary besides the fluctuating closed loop... i can get more logs probably...

 

That means it can pull up to 30% of fuel currently, which of course will send you into the 16s-17s. If you lower that value, you'll certainly end up running less on the lean side in closed loop.

 

Exactly.

I would try -10 and 15 and start there.

When you use a wideband with closed loop the max/min adjustments will always be smaller.

 

ok i will try that.

well ive tried both ways with closed loop.. tried narrowband and wideband and still does it either way.. i only have one o2 sensor and have both narrowband and wideband inputs into the ecu.

did they recently add these parameters onto smanager? because it only recently started doing this like a month or 2 ago.

 

i changed the min and max to -15 and 30 and it helped some.. on the hwy it is fine most of the time now but cruising around town its still doing the jumping thing from 14 to 17 afr