Going rich then lean when shifting

[decipha]

your contradicting yourself

if you stab it and it goes rich how are you getting a lean spike ?

[dleach1407]

When i shift, it drops to 20:1 then AFR recovers really fast. When its cold it stumbles, when its warm it stumbles less. the problem seems better now because the spike is really quick. Its like the enrichment isnt occurring long enough or as the engine decels its trying to pull so much fuel it causes issues. If I am sitting stopped in neutral, I can stab the throttle and it still goes rich (13.5:1)which would lead me to keep moving the manifold volume maybe I need to reduce fn1321. When I am driving and shifting when cold, the AFR rises to about mid 13s, then as soon as I engage the clutch, and press the gas i hit 20:1 then right to stoich. When warm its doesn't go as rich but its basically the same. My fuel should be within 2 to 4% of being perfect in most cruise cells at this point.

[decipha]

13.5 on a 14.7 scale is only .91 lambda that not way rich assuming your not commanding enrichment on the tip in.

Simply kick up the manifold volume slightly to get that nearer to commanded.

if you need transient fuel longer just kick up the transient fuel time constant

cold transients doesnt matter you dial that in after warm transients are dialed in by adjusting the ve correction table which is a multiplier to manifold volume for temp

[dleach1407]

Yeah, I realized I said way rich and edited it but you must have replied while I was making the edit. I dont see a transient fuel time constant. Do you mean accel time constant? Warm is closer than cold but once i get warm, cold should be pretty close too. FN312qd is kicked up 10% over the base settings. I believe that is enrichment on tip in. Should I return that to the base settings?

[decipha]

the accel time constant is just that

unless you have an all stock setup no

[dleach1407]

Thanks. Ill play with it as soon as I drive the car again. I feel confident im really close now and its just a matter of me tweaking it a little to get it where i need it. I checked fuel error yesterday and I am perfect in all cells except idle where im off by 4% still. i already extended accel time constant to 8 and bumped the manifold volume to 10, just havent driven it yet. One a side note, have you ever thought about putting together a list of common functions and what they do? There are a lot of important functions that have no comments, specifically the transient fuel functions. If there was a spreadsheet like for the ecu pinouts with eec-iv and eec-v common functions, and their usage it would make it significantly easier to find information I need. Also I couldnt find any information in the writeups about transient fuels. I didnt even understand what they were until i researched on other sites. 3rd question, what is the password for the xdf? i would like to edit some of the comments with info that makes more sense to me and add comments for some unlabeled functions.

[dleach1407]

I think i went too far on manifold volume. I moved it to 8.5 and that seems to be better but now im seeing 22.4 AFR and its going a little lean when i stab the throttle so i need to move it a little more. How much should i be moving accel time? I increased it by 25% and if anything its worse. Can i 0 out decel time to remove decel enrichment for testing? i locked it in open loop for a short time and the problem does not exist at all in open loop. just an fyi.

[decipha]

You reduce manifold volume to enrich tip in not increase it.

[dleach1407]

You reduce manifold volume to enrich tip in not increase it.

Right. I went to 10, it was going pretty lean, i moved it to 8.5 to add more at tip in. Can i set decel time to 0? How much should i be moving Accel time?

[decipha]

you need to get manifold volume dialed in first. divide decel by half and multiply accel by 2