s300 closed loop running super lean, open loop is perfect!

[EMP]

Hi, my first post here, im from Sweden so the grammar might be slightly off!

This saturday i tuned my built b16a2 at my local tuner, Everything Went fine but after the tuning was complete (In open loop) it would run very very lean in closed loop using stock narrow band o2 sensor.

I have a aem uego but it is not connected to the ecu.

I have not driven the car in closed loop after tuning. but in open loop it runs perfect as stated.

This day i erased the ecu to get rid of long term fuel trim that someone told me might be the problem, its still the same doh.

Even with short term fuel trim set to 0 -0 its goes very lean, out of scale on the aem unit.

The ecu shows o2 voltage going down to 0.1.

is it A: the o2 reads lean fuel mixture and the ecu gets the signal but does not compensate for lean mixture?
B: the o2 got fried at the shop and trix the ecu to Think its actually rich and leans out the mixture, so the value 0.1v is the ecus answer not the o2s answer/input.

How can open loop be perfect and closed loop go super lean with short term set to 0 -0%?


Thanks for input! / Gustav

[Spunkster]

Your grammar is better than many native speakers.

Can you post your calibration as well as a datalog showing the issue. Make sure it is the calibration that was used when the datalog was made.

[EMP]

Thanks! Sure, ill try.

the recording are not very long, did it for my tuner yesterday but he didnt know the answer to this riddle...

But how can the open loop be fine, and then closed go super lean with 0-0% short fuel trim? Is this even possible?

Im not sure if the closed loop recording is with +20% fuel on column 1-2 or not, did 2 recordings and right now i dont know. the problem is the same with 20% extra fuel anyway so i dont Think it matters.

[Spunkster]

Can you also post the calibration used when in closed loop.

[EMP]

Its the same calibration for closed and Open.

[Spunkster]

I need to see exactly what settings you are using for closed loop

[EMP]

You mean this?



narrowband target voltage is 0.51.

i have tried with short fuel trim at 10% 1% 0% no difference... i cant understand whats wrong.

[Spunkster]

Post the actual calibration with all your closed loop settings please.

[EMP]

I dont understand?

The calibration i posted first is the actual calibration that i use right now, i have only tested with different short fuel trims and so on.

But is it even possible that the af Changes when it is perfect in open loop, then i change to closed loop and set short fuel trim to 0%?

[Spunkster]

The calibration you posted is set for open loop. I need you to post the calibration you used with the clossed loop settings you used. This is the only way I can see exactly how it is setup and get an idea of why you may be having dificulties.

[EMP]

It is the same calibration for Open and closed

The Only thing i do is change to closed loop and upload. Does the fuel tables change when i do this?

[Spunkster]

So upload the calibration with the settings you used for closed loop so I can see exactly what they are please.

[EMP]

Like this?

[Spunkster]

Download the most recent beta version of software from the website and reuplod the calibration and see if that resolves any of these issues. I see when you are in open loop the o2 voltage is reading about 3.79V and in closed loop its is reading .1V The narrowband input is a 0-1V input.

[EMP]

is this a known error in previous versions? yes at startup its about 3.79v then when it warms up in a minute it starts to decrease voltage until 0.2 0.1 and it starts to lean out.¨

BUT! even with the short term fuel trim set to zero percent i will go lean on me, have you ever seen this before?

I will try the beta tomorrow anyway!