5.3l Odd Idle Issue

[glosasso]

Just completed a 5.3l swap in to a custom car. I am having quite the issue with getting it to idle it starts and idles for 2 secs then shuts off. my first thought was vats but its disabled. now for the kicker i thought it was killing fuel so i started it then sprayed it some brake clean to see if it was killing fuel. well the idle dropped really low but it continued to run once i stopped spraying the brake clean it continued to run and idle just fine until i shut it off. I have changed the amount of time before it tries to learn idle and it will run a bit longer it still dies. the specs are Custom fabbed headers, ls1 intake, and 36?lb svo injectors. I know at gm pressure the injectors are 40-42 lbs they are white bodys. i have been beating my head against the wall for weeks with this thing please help me!!!!

[glosasso]

The current tune is from the tune file depot because i didn't have a 5.3l tune.

[joecar]

Intake manifold air leak (check port runners, injector bungs).

Did you populate the IFR table with the florwate for those injectors and for your measured rail pressure...?

Did you take into account whether your FPR is manifold-referenced or un-referenced...?

[glosasso]

Injector flow rate was changed and scaled for these injectors i am running an unreferenced aeromotive regulator.I have not checked for leaks yet but like i said if i give it a shot of brake clean right after it starts its will run and idle at 600 rpms wouldn't a vacuum leak cause it to high idle? now once i get it running if i stab the throttle it will rev up come back down almost stall then come back up.

[thunder550]

Is it a stock cam, throttle bdy, etc? Might need to tweak the idle airflow tables a bit.

[glosasso]

Stock cam stock throttle body on an ls1 intake I have tried adding and pulling air in the desired airflow table as well as adding fuel to the ve and pulling it and adding fuel to the cranking ve and pulling fuel and re same with the comanded fuel at startup

[joecar]

So you have a stock 5.3L and the PCM that came with it...?

If it's all stock then the problem would be physical.