Originally Posted by
robgagnon
I had intermittant cut-out with illuminated check engine light just for the brief second it was cutting. Wiring schematic shows that both power and ground to ECU also route to 3-conductor test connector by aircleaner. I ran an extension from this connector to an analog meter sitting in passenger seat and drove around. Power nor ground were disrupted so that showed that relay, harness, connectors seemed ok. Turned out to be ECU. Have not opened bad unit yet, but probably broken traces on circuit board which might be fixable with a resolder, but as Tim says, extra ECU was handy. Some ECUs appear to be interchangeable: I think these two are interchangable:
4YE ECU 89661-28040 86 87
4YE ECU 89661-28060 86 87