96 k1500 misfire

My 96 k1500 with a vortec 305 cpi injection recently started idling rough. Changed the plugs wires cap and rotor. I put in iridium plugs. The engine light also flashes at idle but is not storing any codes. As soon as you start driving everything seems to be fine and the engine light turns off. I looked down the throttle body and it was fairly carboned up, tried some spray in cleaners with no effect. as well I should mention that it is hard to start when warm, you need to give it gas while cranking.

Welcome to AF, fuel pressure tests are in order here, as the entire cpi system is troublesome, there should be stored codes or pending codes, maybe your scanner is a low level design and does not pick up these parameters.