Newbie Truck Norris tune clean up help

[phroggy 46]

All,
I am brand new to the world of tuning and am asking for some help. I have a 2013 5.3 Tahoe with the BTR Truck Norris cam, DOD/VVT delete, Springs, Headers, JET TB, and a Circle D 2400 stall converter. I am feeling that the tune is not quite correct currently. The truck has stalled about 6 times when coming off the interstate and also if you apply the brakes rapidly. It also surges through the brakes in first gear if you are not in a coating situation when slowing down and apply the brakes. When coasting at any speed above 25 the truck bucks and you can hear the drivetrain clattering. It also seems to idle low when cold and warm, in and out of gear, along with a fuel smell at idle. I first thought the smell was due to the exhaust not having a cat installed, have since installed a MF Heavy metal cat and muffler, smell is less but still very noticeable. This tune took nearly 5 weeks to be completed and seems quite doggie honestly. Any help would be appreciated. I pulled a short idle log and the tune from the truck, not sure if I did it right. When scanning in park the spark advance is all over the place along with the idle. Please help yo.

[JLawson240]

I'm currently working on a friend's truck with the same cam. But that's the only mod he has, everything else is stock. I'm new to tuning also but initially I noticed that the under spark>advance>idle adaptive spark control could all be softened by 50%. That helped the timing bouncing all over the place pretty well when I made that correction. I also commanded 20 degrees of timing on the idle spark table in all cells between .40g and 1000 rpm, and plan to try a few more. Target rpm is currently set at 775. Your base idle airflow table looks pretty good to me in relation to the tune I've done. I'm going to make some more changes I've noticed I overlooked when I get the chance. His truck idles almost stock now, but for some reason randomly decides to surge and buck from time to time. I'm hoping by correcting the minimum idle RPM referenced value, and correcting his startup idle airlfow table will further help clean up the idle. I mainly commented to follow along as I'm still very new myself. Whoever did the mailorder tune on the truck completely changed the base idle spark map also, the 3d graph is now completely linear like its all been interpolated. So I hope once those changes are made it idles as it should all the time.

[phroggy 46]

Thanks @JLawson240. I will look at that in the morning and write it then let you know.

[kevin87turbot]

There are a lot of opportunities for better performance in your current tune. The timing curve is way too conservative. The PE delay needs to be eliminated. Burst knock can be zero'd, and torque management can be reduced significantly.

I'll be glad to dial it in for you if you'd like. Feel free to email me [email protected]

[GHuggins]

To start with you really need to be logging as much data as you can - you're missing a lot of the things you need to logging such as torque. Looking at your tune I would say throttle follower commanding negative torque at idle and the torque model being untouched is a decent chunk of your problem. Then you have adaptive idle - you can leave the numbers up, but shift them to the right leaving about 3 cells 0ed out. Lower your idle rpm down to 675 or a little lower and go from there.

[phroggy 46]

Adding log from Cold start through commute to work.

[reubone]

Backstreet Tune try.hpt
Try that. If your idle is to high, lower the effective area min down from 61 2 numbers at a time until your idle is right without stalling

[phroggy 46]

Thanks @reubone. I will give it a shot and let you know.

[phroggy 46]

That is much better. Now if I can get the transmission chugging to go away on decel I will be grand