(94 Chevy SS with CMFI

Wondering if anyone has had a similar scenario.
Truck starts well when cold, but when it has sat for 1/2 hour to 5-6 hours, after it has been run,very difficult to start. Seems to behave like it is flooded, very rich exhaust, stumbles when it initially fires up, and it is necessary to hold throttle wide open to get it going.
I am wondering if the injection unit iside the plenum is bleeding off fuel into the cylinders or maybe it is the Idle Air Control not sensing properly.
Any suggestions?

Pretty common, slight leak in the inner plastic fuel lines under the intake, or maybe a leaking pressure regulator, also under the intake. Good read here:

http://forums.s-series.org/viewtopic.php?t=2278

Thanks for the tip, i will have a read of the link and see where it takes me.