Chevrolet Repair: 95 GMC 7.4 surburban headacke, mass air flow sensor, mass air flow

Question
vehicle would not stay running had a variety of codes egr & missfire also code for throttle accuator replaced tps,egr,ecm,cap,rotor,& distributor vehicle runs great once warmed up but wont stay running cold have been fighting vehicle for over a month magnet was broken in distributor , egr was stuck open 14% cap & rotor were burnt customer thought ecm was problem so had me replace it now im scratching my head ??? fuel pressure well within specs. what next??? this truck has thrown me for a loop!!!

Answer
Hi Paul... i will assume that this is TBI did you remove idle air control and see if it needed cleaning, or that it is working properly, you seem to have covered everything else. the only other thing i can think of is a vac leak...if it's not TBI  did you check specs on mass air flow sensor when cold. another thing to try is unplug egr when cold, i have seen where they will not seat when cold..even when they are new...hope this helped