Need some help with a cold stumble when cold.

[conceptvip]

I have a 2009 ctsv that I'm having a issue with the car falling on its face when trying to light-medium accelerate when cold from a stop. The issues clears up once the car gets some heat in it. Im having a hard time figuring out what it might be and the tuners having a hard time with out having the car in front of him(they are out of state). It seems to me that the car is super rich and leans out once the coolant temp increases. Can someone look over the tune and some logs and give me some advice. Thanks!!!REV 4.hptrev 4 cold stumble.hplrev 4 driving, one wot.hplrev 4 warm stop go.hpl

2009 ctsv stock bottom end

233/248 .629/.615 LSA 116+XX
1200 FIC injectors
103mm TB
airraid intake with MAF

[edcmat-l1]

Main reason is the IAT table has been zeroed out in the colder area of the table. Seen it many times. Tooner needs to put some of that back. Better yet, find a tooner that knows that's the problem.

Edit: There's other work that needs to be done, but that's the main cause of the stumble when cold.

[SiriusC1024]

Both airflow models, but specifically VVE for this issue, are incorrect. This tune has been pretty well massacred.

Add the channel Volumetric Efficiency Airflow to your scanner config then post another log. You'll see what I mean.

[edcmat-l1]

It definitely needs a lot of work but that's not the cause of the posted problem. It's mainly a timing issue. Crappy big injectors and crappy injector data can contribute to it but it's mostly that one table. I've tuned a few hundred of these things.

[conceptvip]

Main reason is the IAT table has been zeroed out in the colder area of the table. Seen it many times. Tooner needs to put some of that back. Better yet, find a tooner that knows that's the problem.

Edit: There's other work that needs to be done, but that's the main cause of the stumble when cold.

Thanks for the advice, stupid question does modifying my table to resemble the picture you attached, isnt that adding a ton of additional timing to the base timing?

I don't know much about the tuning thing and don't want to screw something up lol. Spring time ill find another shop to retune the car in the Chicago land area, this will make it tuner #6 for this setup. Sucks car drives great once its warm but I don't really want a butchered tune in the car. Out of curiosity, all 5 of the tuners all have this table zeroed out and a few of them are big names in the community, why would they do this and not have it set up properly? Once again thanks for the help.

[conceptvip]

It definitely needs a lot of work but that's not the cause of the posted problem. It's mainly a timing issue. Crappy big injectors and crappy injector data can contribute to it but it's mostly that one table. I've tuned a few hundred of these things.

I fixed my mod list, I have fuel injector clinic injectors. I had FID's which were complete junk and never started well when warm.

[conceptvip]

Both airflow models, but specifically VVE for this issue, are incorrect. This tune has been pretty well massacred.

Add the channel Volumetric Efficiency Airflow to your scanner config then post another log. You'll see what I mean.

Thanks for the help. Ill look into rescaling the maf and VE tables, I assume that's what your talking about? Also Ill hook up the wideband and relog with the channel you suggested.

[SiriusC1024]

No I mean actually tune both of them. The scaling is done for the injectors. Now, you have to tune for the cam.

How can 5 different tuners not get this? I guess that's why all the right tables (except torque hasn't been touched) that should be adjusted have been adjusted the wrong way. Reach out to edcmat-l1 here if you want it done right...and well before next spring.

[edcmat-l1]

Thanks for the advice, stupid question does modifying my table to resemble the picture you attached, isnt that adding a ton of additional timing to the base timing?

I don't know much about the tuning thing and don't want to screw something up lol. Spring time ill find another shop to retune the car in the Chicago land area, this will make it tuner #6 for this setup. Sucks car drives great once its warm but I don't really want a butchered tune in the car. Out of curiosity, all 5 of the tuners all have this table zeroed out and a few of them are big names in the community, why would they do this and not have it set up properly? Once again thanks for the help.

It's common practice in these things when you increase the boost and then toon them. I see it all the time. It's basically to keep it from hurting itself when it's colder and the air is much denser. But ya gotta walk that line. Gotta make it drivable at the same time.

Your main timing table is lowered a bunch so you should be able to put some of the IAT timing back without causing any problems. Need to put your knock sensor tables back to stock also. They're set too high. Bet you don't have the least bit of knock retard. That always scares the shit out of me with these cars. If you don't see any KR the sensors are ineffective.