stephen18

233k miles.

Well ive had this car 1.5 years. ever since i bought it felt like it was low on power. I've replaced a long list of things. But, it had been running rough at idle and i cleaned up the injectors by hand/solvent and it DID improve that significantly. So, the carbon build up could be a possibility. I guess i might have to open it up again. Its all right i guess as the starter has had hiccups lately....

Kingsoup

I've had a few problems like this before on previous cars, hard to nail down, I had a Supra once that had a bent pin on the injector and was only firing on 5 cylinders of 6.
I'd find another LS400 at a dealer and go test drive it, you should be able to tell if its faster or not for sure, that dyno was really wierd, HP rise was so flat, but it might have been the dyno, drive another car to be sure!