tbss hard start....

[kbturbo]

I have an 06 trailblazer ss with a built 6.0 stock ported heads, with a pcmforless attitude cam. I have fuel trims perfect, wot perfect, and warm start perfect. The only thing I can't figure out is the cold start.

If it sits overnight, I have to open the throttle in order to get it to start. If I dont, it starts for half a second and shuts down. Once I get it started, I have to apply throttle for appx 15 seconds, then I can let off, and the idle settles perfect! After that, it starts and idles perfect. This is the only thing I can't figure out

I have messed with the cranking ve table and the cranking air table, and not much seems to help!!

I would greatly, greatly appreciate any and all input!!

[Sam88gta1]

Post the current tune file.

[Bill@HPTuners]

Cranking spark table maybe?

[kbturbo]

Here is the tune I'm working with. I feel like I'm back at square one, and am stuck on something soo simple! Hope I can find a fix!

I've tried adjusting the crank advance, to no avail

When i first try it, it gives one half second startup, then I have to apply throttle in order for it to start. Then it starts, runs rough for a few seconds, then clears up, After 10 seconds, it will idle on it's own

Thanks to any and all help

[Alvin]

We have mail order tunes to get that cam very close if you need it. We also go back and touch up the tune via datalogs. I would pay attention to your VE table, cranking VE, and look at minimum idle airflow. Those are key to getting it started right.

[Sam88gta1]

You have too much Start Up airflow. Looks like you simply added a value of 3 to the entire table. You should put the table back to stock and add 20% at the very most.
Focus more on getting the Final Idle Airflow Minimum table in order. You shouldnt need to add more than 30% to this table to get the idle stable.