Alexia56

I have an 05 RX 330 with 119000 miles. Car runs like a top except for this strange hesitation that occurs upon acceleration. I upped the octane to 93 (Costco only has 87 or 93) and it helps somewhat but the problem is still present. The hesitation occurs immediately upon acceleration from a stop and if I am accelerating slowly. If I accelerate a heavier I do not get the problem, but I drive a little on the cautious side. I also noticed it occurs when I'm rounding a curve or turning a corner.
I'm facing having to have the timing belt/water pump replaced but don't wont to do that if I am looking at a possible transmission problem. The car runs very well otherwise.

biggus

Tough to diagnose. Could be it needs a new set of spark plugs (due @120,000 miles). Could need a fuel system cleaning, throttle body cleaning, or all 3. There was a TSB on this as well the dealer does a software update to help sluggish acceleration I believe. I'd do the simple stuff first, run a couple bottles of Gumout Regaine High Milesge fuel system cleaner through two full tanks of premium, this helped me out with our 04.

Alexia56

Thank you so much for your input. I will try the gumout. I don't know what TSB is, could you explain that to me? Thank you.

numbafree

Technical service bulletin. It's a step down from a recall (major liability if it goes unfixed), but something the auto maker needs to fix.

https://www.automd.com/tsb/lexus_m/rx330_mm/2005_y/

how long and how many miles have you had this strange hesitation? how long (seconds) is the hesitation when you try to accelerate.

I know for my 170k mile 2005 rx330, because it's drive by wire, there is always a slight hesitation before the acceleration kicks in.