Hi john i had one of these about a year ago that tied me in nots we checked valve timing,ignition timing & emissions found that car was running very weak scoped O2 senosor & O2 sensor pinned at 0.1v sprayed carb cleaner into inlat manifold & you could see that O2 sensor respond to carb cleaner,could not find any air leaks.My thinking at this point was that ECU could not see what O2 sensor was doing so fitted new ECU which cured the problem.This is the shortend down version of how we got there because the first ecu did not work.