engine starts fine, 5-8 secounds after it runs rough then stalls.

The idle speed is supposed to be electronically controlled. The computer in your car looks at coolant temperature, engine revolutions per minute, load on the engine and then computes what the idle speed should be and used the idle speed control motor to control that speed. Either there is a problem in the circuit or motor or another problem has occurred that is beyond the capabilities of the computer to control the idle speed.