We have a Vans RV12 with a Viking 110 engine we upgraded the electronics also as pre Jan at Viking added a upgraded ECU and wiring harness plane has not flown for over a year. Can't get any help from Jan sent the ECU and wiring harness back three times still doesn't run right Jan will not give up any info on ECU don't know to turn. Does anyone have any suggestions
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Viking 110 ECU
- Thread starter Doug1945
- Start date
12vaitor
Well Known Member
Been down that road on the 110 ECU years ago and I switched to an alternative. A few years ago, Mark Hubelbank started an effort to develop a new ECU for the Viking 110, resulting in the HU708 ECU. I have been flying behind my HU708 ECU for about 5-years now with no issues. Full hardware schematics and software source code are available for anyone to look at and modify. There are some HU708 ECUs and engine wiring harnesses out there, be aware that Jan will blame the non-Viking ECU for any engine or gearbox problems. There is a support group at https://groups.io/g/HondaFit708huECU that you may want to join. I have a spare HU708 ECU, however I have no plan to sell it. I would be glad to share the engine sensor/wiring diagrams I developed if you are interested.
You mentioned you upgraded the ECU, did you have the engine working with the original red ECU? I have an original red ECU with the last firmware update and some documentation on the original wiring harness that I modified to use with MIL-CIRC connectors on the firewall. As mentioned, SDS is another route you can take for a supportable ECU. Ross has done Honda FIT configurations and seems super helpful.
John Salak
RV-12 N896HS
You mentioned you upgraded the ECU, did you have the engine working with the original red ECU? I have an original red ECU with the last firmware update and some documentation on the original wiring harness that I modified to use with MIL-CIRC connectors on the firewall. As mentioned, SDS is another route you can take for a supportable ECU. Ross has done Honda FIT configurations and seems super helpful.
John Salak
RV-12 N896HS
Thanks might try that
Yes it ran fine Jan suggested the upgrade hasn't ran sense
12vaitor
Well Known Member
You may want to consider going back to the last good configuration of ECU/engine harness to see if the engine will run normally. The critical sensors are the two hall-effect crank position sensors to the right of the oil filter. There is a several degree difference between the primary and backup sensors, so make sure they are wired correctly, or the timing will be way off. Other critical item is +12V to the coil packs and injectors and good grounds. Intake air temp sensor and MAP sensor should also be checked. The Viking 110 ECU originally operated in wasted spark mode (fires two coil packs at the same time), the HU708 ECU restored the cam position sensor to eliminate the wasted spark mode and reduce the duty cycle on the coil packs. Not sure if the "new" Viking ECU changed to that setup (you would have to install the cam position sensor).
John Salak
RV-12 N896HS
would you be interested in selling your original red ecu looks like you don't have the original wiring harness we sent ours back to Viking with our red ECU so we have nothing
12vaitor
Well Known Member
