Ls400 slowing down quickly and not accelerating quickly when warm

[Blakegillan]

I have a 1993 Lexus LS400 I just had a new capacitor soldered into the ECU and it did not fix my problem. when the car is warm it will not accelerate quickly and it slows down as if I’m on the brakes. I originally thought it was the brakes and I changed the callipers thinking one was seized and I did not change it it’s only happens when the vehicle is warm and after it smells like somethings burning which is quite concerning. When the car is not up to temp, it drives perfectly. I also am displaying no codes and am at a loss of what to do.  Would anyone have any idea how to fix this? Thanks so much

[Malc]

Blake hi and welcome to this forum

Several members on here have had early Ls400s, including me a long way back, and whilst I have no idea how to advise you I'm sure one or two members here will help where they can

Good luck

Malc

[Spock66]

You need to isolate whether this is an engine fault or whether there is some other factor.

When the problem occurs, does the engine rev freely in neutral?

If it's not the brakes binding maybe the transmission or something else in the drive train has a fault which is putting excess load on the engine.

[BigBoomer]

Try shifting into Neutral when it is slowing down heavily.

If it then stops slowing heavily then the issue is not the rear brakes, differential, or the gearbox.
I would then suspect that the engine management or torque converter has an issue, or could be front brakes seizing due to heat.

If it continues slowing down heavily in Neutral, then the issue is probably rear brakes, diff or gearbox.