userix

My LS460 recently started having a weird acceleration stumbling issue when accelerating moderate to hard. When I do moderate or heavy acceleration, sometimes the car would suddenly lose all power, but if I back off and slowly acclerate, then the car accelerates fine. When these stumbles happen, there are no CEL or OBD II codes thrown (pending or confirmed). It doesn't happen on every hard acceleration, but seems to happen more often now. It's jarring when it does stumble as it's a very sudden loss of power. The transmission shifts smoothly and normally through the gears during driving and doesn't have delayed shifting or any clunky shifts. Would this be an issue with the transmission or fuel delivery system issue (ie injectors)?

Boykie

Fuel system 95%

miket000

Just a guess but you likely do have misfires stored after each drive cycle. The short term misfires usually don't happen long enough to trigger a cel with specific code. However the misfires can still be found here. Narrowing it down to a single cylinder or bank is very helpful.

https://www.clublexus.com/forums/ls-...l#post11339636

jmcraney

Sounds like the “acceleration problem” that has plagued many of the LS460s. It is one of the most discussed issues in this forum. Onset is often associated with oil changes.

https://www.clublexus.com/forums/ls-...-problems.html

userix

Thanks for the post, my issue isn't a gradual climb of the RPM with lack of power, it's more of a completely power cut off when I try to step on the accelerator harder for quick acceleration.

jmcraney

As I said, it sounds like the “acceleration problem” that has affected many of the LS460s. It has also been called the “hesitation on acceleration” problem.

Here are links to just a few of the threads in this forum that discuss this problem.

https://www.clublexus.com/forums/ls-...hesitates.html

https://www.clublexus.com/forums/ls-...n-problem.html

https://www.clublexus.com/forums/ls-...eleration.html

https://www.clublexus.com/forums/ls-...fter-turn.html

https://www.clublexus.com/forums/ls-...e-rebuild.html

https://www.clublexus.com/forums/ls-...be-solved.html

https://www.clublexus.com/forums/ls-...-07-ls460.html

https://www.clublexus.com/forums/ls-...-coverage.html

https://www.clublexus.com/forums/ls-...ind-noise.html

https://www.clublexus.com/forums/ls-...ion-on-go.html

userix

I apologize. I wasn’t clear about the symptom. I forgot to also add that it sort of skips as well during moderate to heavy acceleration. It’s like the transmission is skipping as it’s trying to get its grip as I accelerate moderately hard. It would skip a couple times, jerking me back a forth a few times as it engages properly a second later.

when it does the skipping and stumbling, the rpms drop sharply rather than climb very high (as if it was a delayed up shift).

It’s very quick when it stumbles and skips a couple times. Again during slow and gradual acceleration, it changes gears buttery smooth without any abrupt skipping. Even after the stumble and skipping issue, it would accelerate hard and change gears normally. It’s like if I suddenly accelerate moderate too hard either from a stop or during motion, the transmission is caught off guard and skips and jerks abruptly before engaging properly and changes gears smoothly again.

so I’m not sure if it’s fuel or transmission issue. No transmission codes is thrown either. Shifting from p to r, r to p, r to d and d to r all is very quiet and smooth too and engages right away and no harsh clunking or thumping.

Gerf

Ok, first there was no trans problem shifted smooth etc etc...now the trans might be skipping. What happens when the car is acting up and with your cat like reflexes you immediately shift to neutral and pin it...does it continue to miss or just rev out? If there really are no current codes or pending or in history I would be very surprised by your description of the problem.
Did you find anything similar in the long list of threads that Jmcraney supplied you with?