Engine Stall: Cold

Check fast idle system. See IDLE CONTROL SYSTEM in I - SYS/COMP TESTS .
Perform power balance test.
Perform appropriate test in INJECTOR MALFUNCTION diagnostic chart in I - SYS/COMP TESTS article in the ENGINE PERFORMANCE Section. Use DIAGNOSTIC CHARTS DIRECTORY table in I - SYS/COMP TESTS article to locate chart.
Check for spark using spark tester.
Check spark plug for improper gap or fouling.
Ensure fuel pressure is within specification.
Check ECU harness connector.
Check ECU power source and ground circuit. See ECU POWER SOURCE & GROUND diagnostic chart in I - SYS/COMP TESTS. Use DIAGNOSTIC CHARTS DIRECTORY TABLE in I - SYS/COMP TESTS article to locate chart.
Try a known good ECU.