1UZ going into Limp mode after sustained high rpm

[Mikeyae86]

Info on the car: Its a 1UZ W58 swapped into an ae86. Engine was removed from a 1990 LS400. ECU is 89661-50032, Wiring was done to Nigel Wade's guide.

The car has been running and driving normally for almost a year. Multiple 30 min drives, mountain runs, auto-x events ect.

Recently we took it to a track day and something new appeared. After 8-10 mins of on track ( above 4,000 rpm) the ECU will cut out and go into a limp mode.

When this happens it wont rev above 2500 and behaves like fuel cut. When this happened, i could hold it wide open and it would rev strong from 2200-2500 and bounce off like a limiter. If i cycle the key, it would go away and not return for another 8-10 mins. It seems like the ecu is going into self protect for some reason, maybe its trying to say " im a luxury car stop doing that" Here is a clip from the track day showing it happening and cycling the key to reset it (yes i know i have a driveline vibration)

I continued the rest of the track day after and it was fairly consistent. I was able to cycle the key and re-fire the engine and it would be happy and ready for more abuse

I havent seen anyone mention this before and couldnt find any info on it.

Thanks in advance for any help and input

 

[Mikeyae86]

The only data ive found about this fail safe mode is this:

Once a spark event takes place, an ignition confirmation signal called IGf is generated by
the igniter and sent to the ECU. The IGf signal tells the ECU that a spark event has
actually occurred. In the event of an ignition fault, after approximately eight to eleven
IGt signals are sent to the igniter without receiving an IGf confirmation, the ECU will
enter a fail-safe mode, shutting down the injectors to prevent potential catalyst
overheating.
The IGt signal is relayed by the igniter to the proper power transistor circuit to trigger
the ignition event at the proper coil. The igniter also sends the standard IGf confirmation
signal to the ECU for each ignition event which takes place.