Lean after shift

[Enki]

This has probably been discussed before, but I now run lean after shift on both my 50/50 beta scaled OTS map as well as my previously pristine 100% e85 maf scaled map. Rolling on the throttle is fine, but for some reason, shifting makes it kick up a full point in AFR.

My base map is Stage2+cpCAI+TIH 91 v210, with Cobble magic for 50/50 mix, and AFRs leaned to 11.5:1 in all the open loop tables. Only other thing I touched was the APP translation tables to run my custom curve. I didn't even disable any of the CELs for EGR delete or anything.

Map and screenshots of hugenormous log file attached with color coding (green) for > 70% accel pedal and (red) for AFRs >= 12:1.

Any help would be appreciated.

@phate @djuosnteisn @Bucker @rfinkle2

[atvfreek]

I tuned @bbode0 and his car was doing the same thing. It ended up being his purge valve. Just a thought.

[rfinkle2]

This seems most prominent after the injectors shut off and mashing down on the throttle, but I believe Khopwood was working on that with Cobb in this thread (sorry I can not offer more help)...

shift control folder discussion below (note: condition rich after shift, but could be the opposite applies).

SWAS - DISCONNECT ON A GEN2

[Enki]

Purge valve? As in fuel tank purge valve? That is a shitload of air for that thing to be flowing.

Also my SWAS is already unplugged and DSC was disabled.

[rfinkle2]

Originally Posted by Enki Purge valve? As in fuel tank purge valve? That is a shitload of air for that thing to be flowing. Also my SWAS is already unplugged and DSC was disabled.

The link I posted is titled swas, but there are shift control tables discussed (in the thread) that may be of help.

[atvfreek]

Originally Posted by Enki Purge valve? As in fuel tank purge valve? That is a shitload of air for that thing to be flowing.

I know it sounds crazy. We had his tune just about dialed in, the all of a sudden, lean after shift. We thought it was tune related, so we went through every table including the shift tables several times. Then his car started running lean at idle and he replaced the purge valve. Low and behold that ridiculous part fixed it.

Tappin

[Enki]

I just checked my shift tables, and all the fuel related ones are 1.0 already on my pure e85 tune.

I'll have to look into the purge valve, as I've also got way out of whack trims at idle (it's rich though, strangely).

Actually now that I think about it, this is a tune issue; I started having this problem after changing from my old 50/50 MAF scaled map to one of the new betas. I went back to the old map because the beta map had this same issue.

[rfinkle2]

Originally Posted by Enki I just checked my shift tables, and all the fuel related ones are 1.0 already on my pure e85 tune. I'll have to look into the purge valve, as I've also got way out of whack trims at idle (it's rich though, strangely).

The below is a link of a post that I made in Phate's thread describing the same phenomenon. Could the purge valve be going bad due to e85, b/c the guy I was helping has ~15k I think on his car.

E85 Discussion - HPFP lubrication and Flow issues

I've noticed this specifically on 50/50 cars and hope that if David sees this, and it isn't your purge valve (in your case), he'll be able to lend us a hand.

The wot afr's are being adjusted when rolling into the throttle, but if the injectors shut of, no bueno.

[Boost Addict]

Like @atvfreek said, my purge valve was the case for what you are having. From what I understand a bad purge valve can either cause lean or rich at idle, may be something to look into. I bought mine from here:

Dorman 911-702 Purge Valve | Auto Parts Warehouse

You may also be able to find one cheaper through amazon.

[breakfstincluded]

ma car be doin this on the last fill up.

sputtered on start up, turned off right away so didn't get a code

i has warranty

[Enki]

Thanks for digging this back up @breakfstincluded.

I flashed a map yesterday (brand new map) and had the same lean after shift issue; after getting home, I re-saved the map while ditching all non-table values from the map and I think that might have fixed it. Not 100% sure yet, but yeah.

Also, my purge valve seems fine.

[breakfstincluded]

NP lol, just wanted to document my case to the frequency of this issue. And hear if anyone had any updates.

I'm just on the OTS stage 1 for SRI+TIP and my LTFT have been bouncing around -2.3 to -5.5 so I'm hoping purge valve is responsible.

Will boost leak just in case anyway.

Will try to ellicit the Code at next fill up again and then take it to dealer under warranty

[Enki]

You could try dropping non-table data via ATR; under Edit, Configure Options on the Display tab, make sure both Show Non-Table Data Dialog and Keep Non-Table Data are unchecked, then resave the map. If they already are, then this isn't the issue (though you should make sure you have the latest ATR and base map).

[breakfstincluded]

Just went ahead and got a new PSV from RockAuto for 15, along with a front and back donut gasket for 15 all together too while Im at it.

Will search if theres an install how to for PSV here unless its just very plugnplay.

BTW lots of people are theorizing failure being the result of pumping gas too hard or something of that sort.

To add evidence for this my problem:

-Stuttering and death after fill up

-high 25 STFT at idle

This started when here in Oregon where we combat unemployment by letting other people stick it in our gas hole...

I specifically saw the woman attedant struggle a little and pump several times when I was getting a fill up. I'm blaming here for all my problems because I am perfect.

Stage 1 Safe mode on AP seems to help... I tried uninstalling AP for a while hoping to get the CEL to show dealer for warranty work, felt worse... even worse knowing I'm running lean on top of the low stock Idle FP.

BTW CPO Warranty apparently does not cover it. WTF do I even have this for. Oh right, smoking turbo if it ever happens...

[Enki]

Getting this issue again; more testing tomorrow to see if it's a real thing or just happened once.

[rfinkle2]

Originally Posted by Enki Getting this issue again; more testing tomorrow to see if it's a real thing or just happened once.

What do you have your CL exit delays set @ James?

[Enki]

30; OTS values.

[rfinkle2]

Originally Posted by Enki 30; OTS values.

Maybe not a fix, but definitely worth trying a lower value.

There is definitely trimming going on for both generation speeds in open loop.

Speculating, but you just start trimming right @ the end of your log, maybe just past the delay.

[Enki]

Originally Posted by rfinkle2 Maybe not a fix, but definitely worth trying a lower value. There is definitely trimming going on for both generation speeds in open loop. Speculating, but you just start trimming right @ the end of your log, maybe just past the delay.

It's set to go into open loop at 1.0 load; why would it lock itself in closed loop after a shift, and why would being stuck in closed loop affect AFRs negatively like that when the prior gear is just fine?

Also, I'm fairly certain from glancing at the AP that I'm actually in open loop, just running lean; though I did find a small leak earlier that has since been fixed.

I'll have logs after the mountain cruise late tonight though. Kinda forgot to log when I was thrashing around marking my territory with burnt rubber and exhaust howls.

I'll try that though; drop the transition to 15 or so.

[rfinkle2]

Originally Posted by Enki It's set to go into open loop at 1.0 load; why would it lock itself in closed loop after a shift, and why would being stuck in closed loop affect AFRs negatively like that when the prior gear is just fine? Also, I'm fairly certain from glancing at the AP that I'm actually in open loop, just running lean; though I did find a small leak earlier that has since been fixed. I'll have logs after the mountain cruise late tonight though. Kinda forgot to log when I was thrashing around marking my territory with burnt rubber and exhaust howls. I'll try that though; drop the transition to 15 or so.

Like I said, speculation on my part, but I think you would agree that when the injectors shut off, there is likely change in fueling strategies.


You did hit < 1 load between shifts too.

X2

[Enki]

Then maybe a better test would be flat shift vs granny shift.

[Enki]

Learn something new every day.

So tell me, @rfinkle2;, what unit of measurement is that delay number? Seconds?

[rfinkle2]

Originally Posted by Enki Learn something new every day. So tell me, @rfinkle2;, what unit of measurement is that delay number? Seconds?

Maybe it wasn't changing the delays that fixed the issue. Could very well have been a one log fluke.

In any case, good to see that your car is acting well now and your vdynos on FB look very nice.

Has to be in terms of 10ths of a second if the logs jive with the unit of measure.

(speculation, but it seems to help in many cases).

[Enki]

I'll keep an eye on it.

BTW there's a video of that log:

3-4-5 FFS 16 PSI (EFR MB WGA) - YouTube

3-4-5 FFS 16 PSI (EFR MB WGA) - YouTube