Hesitation only at top of Second gear

[WickedSS2005]

I have hesitation at the top of second gear, but all the other gears 1, 3-5 are fine. Currently I am running a stock LSJ (2005 cobalt ss) with intake and exhaust. I'm planning on running a 2.6" pulley and 60# injectors come this spring, but I need to figure out the issue with the top of second gear. I've bumped the limiter to 7100 in all gears, disabled trq management, changed my maf fail signal (to eliminate cel problems w/ intake) to 12500, and changed my fans/AC settings. I logged a couple runs last night hoping to get a little insight on what my issue might be. It pulls like normal through the RPM band and then falls flat around 6500, almost like i lose all my torque. I can run out first, third and fourth gear to my 7100 limiter with out issue.

I have attatched my stock tune, modded tune, and log file from last night. BTW, Killernutz on this forum has a very similar tune on his '06 cobalt ss yet has no second gear hesitation. Possibly thinking it may be a difference in factory programming (??)

[Julex]

When you press on the gas I saw the rpms jumped down by 500 or so. Have you beaten on this car at all? do you hear clutch trying to grab. I see your IDC drop even though your adding more Pedal, did you powershift to cause the rpms to dip. I'm no expert but It almost looks like your Injectors are fueling crazy when you go PE. Also check your Fuel filter and air filter I guess just to make sure. Don't understand why 3rd+ is still fine but that's where I would personally start. Maybe cause by to high rpm with stock injectors for to long caused damage to them, still don't know why it wouldn't affect 3rd + but good luck

[NoRemorse]

When you press on the gas I saw the rpms jumped down by 500 or so. Have you beaten on this car at all? do you hear clutch trying to grab. I see your IDC drop even though your adding more Pedal, did you powershift to cause the rpms to dip. I'm no expert but It almost looks like your Injectors are fueling crazy when you go PE. Also check your Fuel filter and air filter I guess just to make sure. Don't understand why 3rd+ is still fine but that's where I would personally start. Maybe cause by to high rpm with stock injectors for to long caused damage to them, still don't know why it wouldn't affect 3rd + but good luck

Did you look at the KR? (this is a rhetorical question)

[Julex]

He didn't log KR so that's a no.

[WickedSS2005]

My car is not beaten on. I baby this car unless in a race (which is rare) and have yet to take it to the track. Never powershifted my car.

There is no KR, throughout the log file it shows 0 KR.

I followed advice from the RLforums and changing my MAP to 235 across the table has fixed the hesitation in second gear.

[Julex]

Make sure your logging total knock retard, which I didn't see on your file.

[WickedSS2005]

I'll change that on the log config today, but I'm not sure I'll get to test second gear all the way out as winter is covering the roads.

[MMGT1]

Highway??^^^^

[NoRemorse]

My car is not beaten on. I baby this car unless in a race (which is rare) and have yet to take it to the track. Never powershifted my car.

There is no KR, throughout the log file it shows 0 KR.

I followed advice from the RLforums and changing my MAP to 235 across the table has fixed the hesitation in second gear.

You are showing 0 KR because you are not even logging it. It could be pulling 15 degrees of timing and you would not even know!

[Julex]

Yea that's what I noticed he's running on default config which doesn't show alot like KR ECT and a few others that help you when tuning. the Cobalts and Ions use Total Knock Retard PID rather then others which use just Knock Retard PID

Good luck. Btw log MAF hz Iat 1 and 2, Ect and KR and those will add to your ability to see what's going on.

[WickedSS2005]

You are showing 0 KR because you are not even logging it. It could be pulling 15 degrees of timing and you would not even know!

Yea, that's what I was saying. I didn't record any. I used the wrong configuration. No need to get all twisted.

[c24s/c]

log your duty cycle on injectors.

[WickedSS2005]

I got it all taken care of. BTW, 0 KR on the log I ran last night. NoRemorse, take an anti-anxiety in the morning and you'll be fine.

[Julex]

You say for him to chill, but he was trying to help you also.... Especially since KR can be the cause of many problems and we can't tell you unless we see all parameters like KR sensor. Atleast you got it fixed what was it BTW?

[BrianWest]

Yea, what was the fix? I have some hesitation in 2nd and part of 3rd.

[WickedSS2005]

Changed my Desired MAP to 235 across the table. Max is 255 and as NoRemorse told me on another forum, 235 will only allow a max of 19PSI. It's fine to make it 255 to attain max boost if you're set up for boost higher than 19psi. I've got the stock pulley still, so 235 is all I need.

[Julex]

You say desired MAP?? I don't think I know where that is exactly. I must be missing it lol? I know once you say it I'll say duh, but I just searched over and over nowhere. I would have guessed in TQ management since you said it allows you to run more boost. but again still don't see it?


Edit* I just looked in the help file and saw that it's under boost control but there is desired torque and Steady state, which both values are 738. Please enlighten me

[WickedSS2005]

Engine > Torque Management > Supercharger. On that screen, under Boost Control in the upper right there is a table for Desired MAP. I have a 2005,a nd I believe the 2006 cobalt ss/sc shows Desired Torque if I remember right from my friends '06. Same table, diff name.

[Julex]

Not only different name but has different parameters, and controls totally different. That's probably why they changed it between them. Good luck.

[NoRemorse]

Not only different name but has different parameters, and controls totally different. That's probably why they changed it between them. Good luck.

06+ have a totally different TQ management system than later years. It actually has a lot more control IMHO.

And wicked, I was just trying to help, no need to 'try' to crack jokes or anything like that. I was just posting in multiple places so you would see it.