I have a 1993 Ls400 around 130k miles and all stock to my knowledge. The car has poor acceleration from a dead stop and sometimes even moving under 30mph any guess? Makes very little power until around 4K rpm. If I try to do a brake stand the rpms go to 2k and stop basically. Also making a "lifter tick" read about the buckets in the valve train is that a bad issue? Mainly worried about the acceleration!