My 92 Gmc 5.7 Runs Rough At Idle And Low Rpm When Cold. Has 155,000 Miles. Have Replaced Plugs, Wires, Cap, Rotor, Egr, Control Module And Fuel Filter. Idle Surges At Start-up And Occasionally Dies. Starts Easy, Runs Ok At Rpms Above 2500 Acts Like A Carburated Engine With No Choke.

Have you Checked the Timing by any chance?