lean at tip-in/sudden acceleration. no fix!

kaj · Post by **kaj** » Mon Oct 30, 2006 12:59 pm

i'm still playing with my tune, but i have a problem i can't solve:

while accelerating from a stop or at low RPM, when i give the car a decent amount of throttle, the car "misses" or stumbles before accelerating. while watching the wideband, i can see it go lean for a bit. it appears on the datalog.

while driving:
2:10.441
2:16.389
2:34.952
4:24.918
here, i stabbed at the throttle while driving to provoke the lean condition:
5:24.085
5:26.710
5:28.088

details:
stock B18C5
Hondata S300
630cc injectors
turbo kit, blah blah.
Walbro Fuel Pump.
all else is stock

what has changed:
valve job
switched from JDM to USDM pistons.
switched from -6 fuel feed line to -> line that goes from -4 (1/4"), from fuel pump, to -6 under car, then back to the steel -4 line on firewall. (all due to repairs).
switched from after market fuel filter to OEM.
switched from STR fuel rail to stock.
switched to smaller intercooler.

hondata tune:
http://mywebpages.comcast.net/kaj7502/tune.skl

datalog:
http://mywebpages.comcast.net/kaj7502/fwy.s2d

anyone have an idea?

so far i've tried adding fuel to the tip-in trim.. no help. i've re-added the 2% fuel trim the tuner had in cyls 2 and 3.. no help.

it doesn't matter what rpm i'm at, what vacuum/boost, etc... i have a sick stumble when stabbing the gas pedal.

any help would be appreciated. thanks

kaj · Post by **kaj** » Mon Oct 30, 2006 4:48 pm

*edit.

locash · Post by **locash** » Mon Oct 30, 2006 5:44 pm

How much have you added to the fuel trim? What is your base fuel pressure?

kaj · Post by **kaj** » Mon Oct 30, 2006 6:18 pm

locash wrote:How much have you added to the fuel trim? What is your base fuel pressure?

the map is the same as it was before i swapped out the parts above. right now i have nothing added, anywhere. i tried adding some in and it made no difference.

fuel pressure is stock. i never mess with it.

locash · Post by **locash** » Mon Oct 30, 2006 9:15 pm

When you say that you added "some", how much are we talking?

kaj · Post by **kaj** » Mon Oct 30, 2006 9:23 pm

locash wrote:When you say that you added "some", how much are we talking?

as stated above: 2% on cyl 2 and 3. my tuner did that for safety, but i took it out because i used to have the OPPOSITE problem that i do now: it would bog when shifting quickly or stabbing the gas pedal. once i took that out, the car ran like a dream.
i see no change when i add it back in, now.
on tip in, i tried 1% and 2% but saw no change. i didn't think it would seeing how i can hold the throttle at a constant, low rpm (ex: 2k), then stab the gas and get the same, lean condition... so it's not only a problem at tip in.

it seems to be getting worse. i was cruising home today and as i'd come to a stop and the car is under decel, the wideband would show "air", as normal.. but then, i'd come to a stop and it would stay lean long enough that the car died :(

p.s.: thanks for the help. i have a local guy that could probably solve this problem for me, but i think i've bugged him enough for a while :D

Post by **Spunkster** » Mon Nov 06, 2006 12:20 pm

I think you need to get it retuned since quite a bit has changed.

kaj · Post by **kaj** » Mon Nov 06, 2006 12:43 pm

Spunkster wrote:I think you need to get it retuned since quite a bit has changed.

i know :( i thought i could do it myself..

well, i decided to just ditch the turbo kit and go N/A, anyway. i have school coming up and i need to be able to concentrate on that, and not on a car that gives me trouble 24/7.
i'm tired of messing with it. i'm outta the boost game.

now: to try and squeeze every bit of power i can out of my stock motor hahaha