HELP K24A2 swapped 08 si jerking issues

[EmceeWrenn]

whenever i let off the throttle i get a fairly aggressive jerk from the motor, also when cruising at a single speed with cruise control or just driving around any time im holding the accelerator steady the car will JERK bad whenever the motor goes into a "coast" but when accelerating at all i dont get the jerks. Thanks in advance for any help!

[Spunkster]

Have you discussed the issue with your tuner?

[EmceeWrenn]

Uhhhh I’m broke on unemployment LOOKING FOR WORK if anyone needs a guy in the Sandy, Oregon area I’m you

[CalibratEd]

Uhhhh I’m broke on unemployment LOOKING FOR WORK if anyone needs a guy in the Sandy, Oregon area I’m you

Post the calibration file you are running and a datalog. I can take a look at it.

-Ed

[EmceeWrenn]

Thank you so much Ed you rock!! here is a wot pull and a freeway cruising log.

[EmceeWrenn]

update on this it doesn't jerk so much when I'm at freeway speeds but it does do it Bad in first gear like my driveway is between a quarter and a half mile long and gravel and the trip up and down it SUCKS if your not speeding up to ablut 10-15mph and then stuffing the clutch to coast so the motors not jerking the car.

[jeffx]

Can you post some logs of it doing exactly this?

the only thing i see in your freeway logs is that it's running much leaner than commanded on your pulls (e.g., command is 0.75 Lambda, actual lambda is 1.0). So the MAF scaling is off or your fueling tables are wrong? I'm not real familiar with FlashPro tuning on that platform, but it's something that stands out to me right away. Post logs of the bucking or surging or whatever's happening and maybe we can see what's going on there.

[EmceeWrenn]

I will get some logs of it doing that in just a minute, my driveway’s literally the best place to do this. Hopefully it’s something simple. Could the MAF be going out and that’s why it’s pulling fuel and leaning it out during wot?

[EmceeWrenn]

Update to this, the surging or jerking basically stopped. Only ever does it in first gear now I think it’s just the computer learning and getting fuel trims set and what not. Idk for sure but I know it’s not nearly as bad as it was when I first put this map on the ECU. Now that being said I had a misfire check engine light for each cylinder and then the random misfire code also. I cleared the codes and my car would not start. Or it would start but immediately die out like it lost the tune entirely. So I re-flash the map and boom it starts and runs fine. Anyone have any ideas on why this is occurring?

[jeffx]

can you post the mods you have on your car? Intake, exhaust, header (cat, etc)? I see you have a MAF-based tune enabled in your calibration. If you're using an aftermarket intake this is probably why your lambda readings are off by so much