MoTeC Global Forum

Hi,
we are having a problem with the motec randomly turning off. You can see it in the log at 40 min. This happened on the dyno. What could be wrong?

Thanks

What application is the ECU used in, and how is the ECU mounted?

Looking at the engine speed in the logging and a few other parameters, my guess would be a motorbike, or motorbike engine in an application.

In motorbike applications, particularly when strapped onto a dyno if an ecu is solid mounted with no or insufficient vibration isolation that the high frequency harmonics can cause the ECU to shut down.

If this is the case, try unbolting the ECU from its current mounting, and hold the ECU for a power run, or sit it on a piece of foam or something to insulate it from the chassis and see if the issue re occurs. If this rectifies the issue, the mounting of the ECU needs to be revised. In many factory installations, the ECU is either encased in a rubber/foam insulation, or mounted in a fashion to isolate the ECU from any vibration or harmonics.

This applies in other applications as well, however the harmonics are not typically as extreme.

For use cases like this we recommend that a ruggedised ECU is purchased.

It's a yamaha r6 engine in a fsae car. So yeah vibrations a pretty harsh. Engine is solid mounted. Thanks for the tip. Will try to mount it differently.

iivvaann12 wrote:It's a yamaha r6 engine in a fsae car.

iivaann12, can I ask you 2 questions arising from your log file? Am I guessing correctly in that you had a battery charger on the car for the second half of the log file? And are you running this as a total loss system, as it seems to be not charging at all? Thanks, Sean.

It is charging just it is discharging more than charging. Fans were on the whole time. Two fans each draws 5 amps, fuel pump 8 amps, water pump 3 amps, rest of the system aprox. 5 amps so in total 26 amps on a 4Ah battery which means it would completely discharge the battery in 9 mins. To be charging properly it constantly needs to be over 5k rpm. Here you see the engine is most of the time on idle. Dyno session was 30 mins before it was cut short with oil going everywhere because the silicon gasket wasn't put on properly.