96 Century won't start when cold

96 Buick Century 3.3L starts but immediately dies when temp is below 30ish. ( will run for half a second or so ). Runs fine when it does start. No rough idling or starting. Fuel pressure above 45 psi. changed air intake temp sensor, no help. code po601 comes up, pcm memory failure, but I thought this would affect problems reguardless of temp. Any ideas would be welcomed. Thanks