double06

The car has some major mods - 454cid, 243 / 259 at .050 .660 lift cam, fast intake, 102 TB, headers, CAI and a few other odd and ends but all NA. When I start the car cold at idle it will run for about 5 seconds then dies. Start it up again (idle about 900 rpm or so) and it will run (may die a few more times) but gets better when car warms up. Now I drive car 20 minutes turn car off and come back 10 minutes later and has a problem keeping an idle again running 5 seconds and stalling. Once again after about 30 seconds or so of running it is OK. When you are coming up to a stop light it does occasionally, have a issue sometime of the idle fluctuating from 900 to 1400 about 3 or 5 times before settle back at 900. I know I need to get back to tuner but what are some ideas on what it could be here? Throws no codes right now.

Frans96ss

Its more than likely mostly in the tune

TurboLX

If the fuel injector data is not exactly matched to what you hardware really does, you will notice it more in cases like this where you have a difference in cold start and warmed up fuel control. It's possible that either the injector data was wrong from the start (and they tuned the warmed up part around it) or they just didn't map the airflow correctly in the first place. All of the cold start fueling is a modifier to the base fuel control, so getting the base exactly right first is a prerequisite for good cold start and idle control.