Ok so I basically flattened the air temp correction table to try and cure a rich condition when its colder outside (around 60F). For whatever reason I can't make the car run at the correct 14.7 AFR with this table like it does when its hot outside over 90F.

I'm wondering if this is an artifact of using the fuel temp sensor as my air temp input. Any insight would be nice.

 

Confirmed it this afternoon with a full .5 AFR difference. Now that its hot the car runs totally normal at 14.7AFR. Need to find out what i can do to fix this.

 

Are you talking about the MAT scaling table?

 

no there was something in my fuel category labled "air temp correction". It likely doesn't correlate at all so i'm giving up on it.

The MAT table shouldn't be wrong the logged values are producing what i'd consider expected results. Those results just don't seem to be applied to the fueling equation where ever that may be.


Notable items:

EGR system is disabled
Cold temp ignition tables are enabled
Set to full time open loop (for tuning of course)

 

I thought someone mentioned that the stock air temp tables compensated for air temp? I assume this is the "relative air density vs temp for airflow/hz" table. It is strangely odd however, going cold would provide more dense air to the motor and it *should* lean out. That it however unless the stock air temp compensation table is a little conservative and/or it is just a bit too much compensation for the SD.

 

This is the table I am talking about.

 

Is your WOT affected by half a point, too, or just idle? If just idle, I would chalk it up to normal variance and start running in closed loop and let the trims do their job.

From what I know of the SD code, the temp compensations are the same as if you were running a MAF, except that the temp is measure where your IAT sensor is instead of at the MAF housing, which at idle, should be nearly the same.


Eric

 

Doesn't seem to be greatly effected so i'll have to agree. I'll just enable closed loop again and get the ball rolling.

 

Definitely strange I was thinking the stock table compensated for too much but i think it may just a product of open loop forced on. I plan on setting the bits back on and loading the rom onto the speed density thread.

 

So its just at idle your lean? I thought it was WOT, disregard my comments then.

 

really the whole thing just goes a bit rich so i'm unsure i'll just let the o2 sensor compensate for it i guess

 

Half an AFR at idle is nothing, nothing to worry about. Let the closed loop system take care of it.