1985iroc

i bought a 1985 iroc a couple weeks ago it has a 305 tune port it in when you start in when its cold it wont stay running unless you feather the throttle once it gets warm it idles fine then when you give it gas it back fire put a new coolant temp sensor in it also plugs wires cap and rotor and throttle position sensor the timing is fine and not throwing any codes it i unplug mass air flow sensor it runs worse any ideas to what the problem might be would be greatly appreciated im at a lost thank you

Z284ever

Clean and lube your IAC and see what happens.