Afr's set then next start up or drive the Afr's are off

[nathanhardy]

As the post states I'll get it tuned in pretty good at idle no surge, car runs great maybe it's my ocd but the next time I drive it all around the same air temps and driving style the Afr's are off I can figure out how to get my wide band more stable any help would be great

[nathanhardy]

All the correction are off for the tune in is asking my ego to +-2 too much to ask? Sometimes 5-6

[elaw]

It's pretty hard to help when we know nothing about your setup! In addition to a tune and preferably a log file, tell us what engine and other hardware you're using.

But I will say in my opinion EGO correction of +/- 2% is too much to expect. I consider my setup pretty well tuned, but between intake manifold heat soak, changing weather, and other factors, it sill will go close to +/- 10% at times.

[turbo conversion]

It's pretty hard to help when we know nothing about your setup! In addition to a tune and preferably a log file, tell us what engine and other hardware you're using.

But I will say in my opinion EGO correction of +/- 2% is too much to expect. I consider my setup pretty well tuned, but between intake manifold heat soak, changing weather, and other factors, it sill will go close to +/- 10% at times.

I agree, +/- 10% EGO correction across the board at all temps. is a very good tune.

I don't know what factory tunes are set up for but I don't think it would much tighter than 10%.

David

[nathanhardy]

I'll post a msq and data log a little later today last night I noticed that I shifted my ase back to 160 from 180 so that was why my fueling was off at restart... Still not as stable as I would like it to be. I have a friend who bought a built sti not sure what's been done to it because he did find out it was built till someone in the car club told him who's it was.. Anyway his idle afr is rock solid at 14.7 and as he goes into boost its steady too I've never seen a aem wideband do that leading me to believe that there's some I can do better... Also I realize I'm a different setup running a vr6 turbo vw golf

[turbo conversion]

Good Luck with that

David

[nathanhardy]

so today running it everything was lean till ego kicked in and added around plus 15 to the fuel. I feel like something is fighting the ecu, since day one tuning it. I'd sure love and appreciate the help. so ill need to look at the ase and warm-ups for the lean during warm up, but what's killing me is I feel like I have a great ve table so im moving on to baro correction since I drive canyons and mat density correction for the temp change besides ego what else has fuel control?. what has got me though is yesterday my friend has vems on his audi and that thing when he changed something you could see it right a way mine seems to take a cycle or 10 and slowly changes. also im not quite sure how to tune for afr lag between my gauge and ecu as well as know for sure if it calibrated correctly since its the wonderful aem master piece!! anyway thanks again gentlemen! just a few large learning curve issues im sure someone wise can teach me.

[thedrew]

double check your dead time calcs....i got bit by that. verify while running the calculation is correct given the voltage

[lagos]

I had the same problem. The solution was to tune the injector battery voltage correction, by disconnecting the alternator oval plug (not the main power lead) and adjusting that value so that the car has the same afr at 11v as it does at 14v with the alternator connected.
This fixed the majority of the inconsistent fueling issues from one day to the next.

Tuning the dead time helped a lot as well. I managed this by guessing a value based on what information I found online, and then changing it up or down from that value. Basically a trail and error approach to see what helped make the fueling even more consistent.

[lagos]

It's pretty hard to help when we know nothing about your setup! In addition to a tune and preferably a log file, tell us what engine and other hardware you're using.

But I will say in my opinion EGO correction of +/- 2% is too much to expect. I consider my setup pretty well tuned, but between intake manifold heat soak, changing weather, and other factors, it sill will go close to +/- 10% at times.

I agree, +/- 10% EGO correction across the board at all temps. is a very good tune.

I don't know what factory tunes are set up for but I don't think it would much tighter than 10%.

David

Using OBD2 loggers, I saw about +/- 5% in short term fuel trims on most OEM tuned ECUs, is anything in that range is great on MS as well.

[nathanhardy]

It's just weird that I can't get constant results day to day... Like tonight 63 degrees tuned in with auto tune car idled and drove fine! But I bet tmrw it'll be off... I guess I need to mess with MAF air den more to fine tune it at this point.