Trouble Running

I have a 77 280z that is fuel injected. When the car starts (sometime it doesn't) it will idle up to around 1200, and run well until the throttle is advanced. As soon as that happens the rpm's bottom out and the car dies. Occasionally, the car will start, but will only idle at about 600 and then dies quickly. Here is what I have done so far:

New fuel pump, good pressure. New EGR valve. New air regulator. Cannot find any vacuum leak. When the car runs, the exhaust feels fine and there is no visible damage to the exhaust system. Cannot find any obstruction in the air intake... I am running out of ideas, can anyone help? Thanks very much.