Back to the FD791D. Replaced coils , { thanks for the info} engine now starts but runs rough. Disco the . Vacuum Pressure Sensor, engine runs much better, replaced pressure switch and vacuum tube, same problem. Any ideas!!
Over 30 years in the mower business, Have my own shop. Usually no problems trouble shooting problems. Have the inter connect for trouble shooting this type of engine. this one has me stumped. Starting to think something with the coils
Wiring from coils to ECU checkout good. Have tested ECU on on other unit, works fine. discoed kill wire to ignition, tested injectors, they work. This one has me stumped. Starts on either, so coils are working.