Acceleration Or Cruising

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.
Ensure fuel pressure is within specification.
Ensure there are no vacuum leaks into intake system.
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.