buch

I'm noticing just the slightest 'hitch' in power delivery in second gear at about 1,500 rpm. My speculation is that this is the torque converter locking up. Any other thoughts or knowledge on this? Thanks, Doug (new member though have 4,000km on my machine in the first two weeks down the coasts of Was, Ore and Cal, and then back until the centre of those three green states). Best, Doug

F1nALMSfan

I think the torque converter is looked out after 1st. Do you notice any humming or ticking in the car at idle? I have seen people that have had the fuel pump issue also have noticed a slight hesitation in power delivery. I'll test it out in my car tomorrow morning and see if there is anything similar going on with mine.

Just for clarification, what settings are you experiencing this in? Sport + and manual mode?

Thanks,

Kevin

buch

I'll check what settings this occurs in but I've noticed it in 'Normal' for sure. No humming but a bit of ticking at idle. Thanks for your help.

F1nALMSfan

No problem. Look at the bottom of this page, there is a video highlighting the sound of the faulty fuel pump. Something to be aware of for sure.

https://www.clublexus.com/forums/rc-...el-pump-3.html

buch

Thanks, I'm not getting anything like that sound (yet :-)). I'll report back on mode-related hesitation after some experimentation. Regards, Doig

oohpapi44

iTrader: (1)

Pictures are a requirement Sir....

Z3NK1

iTrader: (2)

I've noticed the slight hiccup while accelerating in second gear as well, in all modes. I was just going to mention it to the service department on my next visit.

F1nALMSfan

I noticed this as well this morning on my way to work. I think what I was experiencing was possibly loss of rear wheel traction for that split second and the car's TC kicking in, although no light flashed. I would have to try in "expert" mode to see if it was repeatable. I also only have 750 miles on the car, so still in break-in mode, on very new tires.

I'll comment again when I know more.

buch

Fair enough. I'm working out n my forum 'privileges' to qualify for advanced posting. Stay tuned (pun intended) 😎

buch

Thanks. Let us know what you hear. Regards, Doug

buch

Mine is not TC as it's at very low throttle demand. It almost feels like a shift even though I'm running in manual (which I prefer). Regards, Doug

F1nALMSfan

So I took the car out for a spin tonight for a long trip to get gas and when in sport + I was able to recreate the slight hesitation a couple of times, but not every time. I did a number of dead stop to 70 mph runs, experienced it in maybe two in the maybe five or six times.

Just like you say, it feels like a shift, just much more subtle. Not sure if this is the precursor to the fuel pump issue, or just how the car is. Car is going in on Thursday for my 1000 mile oil change, so I will bring it up. I'll let you know what/if I learn anything.

Kevin

Flilady

I brought my car in for this very reason last week. I informed them about fuel pump issues I have read about...and they could not find anything wrong with the car. When I insisted, the Foreman took me for a ride and could not sense any type of hesitation either....I think he was hinting that I was being too 'gentle' with it! Um no. He did say oil temp can affect performance by 30% until it reaches the optimal temp.....will keep my eye on it I guess

buch

My other speculation on this is a simple discontinuity on the 1000s of fuel maps in the software as influenced by throttle position, rpm, etc. and possibly even oil temperature as noted above. I'll be asking more about it. Regards, Doug

buch

I've narrowed this down to being in second gear below 1800rpm and experiencing just a slight hitch in power delivery at low throttle passing the 1800 rpm mark with the revs dropping slightly to 1700 rpm. I'm pretty convinced this is the torque converter locking up as it would explain the drop in revs and is how I think the torque converter is supposed to behave.

It doesn't seem to occur in any of the D-modes (only manual) which may be explained by the automatic transmission holding first gear such that the revs are already above 1800 when second is sought. If so, you can avoid this idiosyncrasy by shifting to second when the revs will be above the lockup threshold.

I'll be asking at the dealer when I go for my first service, but I'm not optimistic they will know more than me at this point. Overall a transmission reflash would seem beneficial.