wierd ideling problem on start up

hi..i have a wierd problem that ive been working on fixing for a while but i cant figure it out..its a 2000 firebird ws6 6spd.. i put a bigger cam on it..ported heads..headers and many upgrades..the problem is when i start the car on a cold start it starts up fine, like when the car has been sitting for a little while, but when i try and start the car when the engine is warm it wont want to idle out right away, it takes about 10 secs of surging to get it right..i cant figure out what the problem is..its wierd that it doesnt do it when its cold??? any ideas or things to try? any held would be good thanks

jeff

i'm assuming you had the ecm tuned properly for all those upgrades?

yes the dyno tune was my last upgrade so everything should be tuned accordingly..

yes the dyno tune was my last upgrade so everything should be tuned accordingly..
Don't count on it. The dyno tune is usually just to get the engine to run right at part throttle through WOT and make max HP. Speaking from old OBD I experience, there are several places to "tune" for starting. There is a pulse width (PW) multiplier vs temp, PW vs # of revolutions while cranking, PW vs battery voltage... It sounds like maybe you are either too rich or lean during a warm start and the PCM is trying to sort things out.
What you need to do is have a scanner hooked up and running as you start the car warm and see what all is going on when it is surging. It could be something as simple as a sluggish IAC.

ya cuz sometimes it puffs out a little cloud out the exhaust that smells like gas..its a brand new iac sensor..when it was at the dyno he tried sorting out the starting problem but he had no luck..

ya cuz sometimes it puffs out a little cloud out the exhaust that smells like gas..its a brand new iac sensor..when it was at the dyno he tried sorting out the starting problem but he had no luck..
Sounds like you need to shorten the PW in the warmer engine temp ranges.

which can not be done manually correct?