Just had the timing belt (TB) replaced by the Toyota dealer using the Aisin kit. It was last replaced 8.5 years and 85k ago. The radiator needed to be replaced so it made sense to replace the TB, tensioner, water pump, radiator, hoses, and thermostat.

With the new TB, the car is more responsive. Particularly from a standing start, car is a bit quicker and "livelier". It also feels better when driving. I don't recall this phenomena when I had the TB replaced on the '02 or '03 LS430. Any thoughts?

 

I am guessing you had the battery disconnected for a little while during the maintenance work. I bet the engine computer dumped it's learned settings and is at default values.

It may be a good time to clean your throttle body as well.

 

Im dumb lol, i kept reading the "TB" as throttle body 😄 and was thinking "ya, that makes sense"

 

Its a placebo effect unfortunately, changing a timing belt wouldn't make the car faster.

 

These cars are terrible for the learning effect and resetting by disconnecting the battery increases the responsiveness and starts the learning all over again. If in fact the battery was not disconnected the timing belt had probably jumped a tooth. I disconnect my battery every few months when I think about it to reset. What I have seen over all these years is it doesn't matter how you drive it always becomes more sluggish from the learning effect.

 

+1

Hot + Dry = Sluggish

65° + Damp = Bat out of hell

 

The placebo effect and the positive result of disconnecting the battery would be fine. I am not looking for any increase in performance. I was just concerned that it may be the result of the work being done improperly. So far so good, the car is running great.

 

The thread title has now been changed to avoid potential confusion, and to make searching more productive.

Thank you moderators.

Please contributors, stop using "shorthand".

 

OK, maybe the TB change DID cause an increase in power or whatever. Suppose that the last time it was changed the timing was off by just one tooth. Then the new belt was replaced by someone that got the timing right. I am not sure how much difference one tooth would make.

 

The car would throw codes, run like crap and or idle poorly if the timing was off.

 

One tooth would make that much difference, I dont think so.

 

1 degree of timing makes the difference between melting a piston and the car running great. If the timing was off the car would go into safe mode and throw codes and reduce engine power.

 

Nerd alert!
One tooth = 7.5 degrees.

 

The highly most likely reason responsiveness was increased was the battery was disconnected as to be done with a tb replacement. For anyone that has not done that just try it and you will see the difference that the learning curve does.

 

Stretched belt does cause a slight shift in cam timing, enough to be noticeable? Maybe.