Hello, while driving my 91 LS400 I decided to change the ECT PWR/Normal to Normal, the car drove fine, got home and parked it while still in Normal.
Next day the car is having major difficulty starting and once started it would idle very rough like a cylinder misfiring and died on me. Took me a minute but I decided to try putting the ECT PWR/Normal back to ECT PWR mode and voila! The car started up and now runs fine for the past two weeks.... I'm guessing my ECU or transmission is going out?

If anybody has any information they'd like to add I'd appreciate it!

 

That sounds extremely odd my friend. I'm wondering if you have an electrical issue with wires in the trunk hinge...

 

Very well could be. I since repaired a slightly broken wire in the hinge, but I haven't changed it back to Normal to test it out yet. My ECU and gauge cluster are being repaired at the moment so can't drive it.