When i was coasting down a hill the other day i noticed that when i pressed the gas it would take about a half a second before i saw the revs jump. In fact if i tapped it real fast, my foot would manage to leave the pedal before the rpms would respond. I was wondering if this is normal. I know it wont be instantaneous but it seemed a little slower than i would have expected. It doesnt seem like it would be a big problem, im just wondering if its normal or if no one else has seen this... I can call the dealer i guess.
Thanks

 

I have an 05 xb and it does the same thing, and I have seen posts on here pretty regularly of people saying the same thing, not sure if theres a fix, maybe modifying the throttle a little bit would help, but it doesn't bother me that much so I couldn't tell ya.

 

It's that new electronic accelerator. No cables involved just sensors or something like that. My VW had the same thing and i hated it. But ive gotten used to it., still don't like it but i'm dealing with it.

 

I had the same problem with my Dodge Dakota and to a lessor degree, my XB2. I fixed it on the Dakota by modding the TPS. It involved removing the bushings from the TPS mounting holes and rotating the TPS slightly to achieve the desired voltage at closed throttle. Throttle response was much improved afterward. I got the idea, desired voltage and instructions from some Dakota newsgroup. I haven't looked into modding the XB2 TPS yet.

 

I called the dealer and he said he hadnt heard anything about it but i could bring in the car and he would check, so ill do taht sometime soon.
When i googled the issue i came across a few threads that mentioned it as a problem in the Camrys, and the new XB does use a camry engine.....

 

My friend said its the new throttle by wire systems on cars these days.
Anyone else heard about this thing, or solved it?

 

throttle by wire is sensors and electronics no cable just like we all have said already. But yes that is the actually name of it "throttle by wire" i couldn't think of it earlier.

 

I am not a big fan of drive by wire, it's really difficult going from my 3000GT to my gilfriend's tC because it causes me to rev funny when shifting in the tC. Unfortunately it's what every company is doing now so I guess I have to deal with it. :-/

 

yeah, it is the throttle by wire system. it is normal. nothing to worry about it. to reduce the delay, your options are lightweight crank pulleys and/or lightweight flywheel.

 

I've heard it's also a problem for the RAV4 with the same 2.4 engine. With so many vehicles affected there must be a work around out there somewhere.

 

If the solution is lightweight crank pulleys and/or flywheels, the problem certainly isn't the drive-by-wire throttle system. One has nothing to do with the other.

 

is your car an Auto? I haven't noticed that problem in my 5-speed xB, but did notice this in the Auto '05 tC... According to the dealer I talk to though, they had fixed that by the '06 models.

 

You're right Scionfred, the lightweight flywheels and under/over driven pulleys alleviate the symptoms felt, not necessarily address the actual root cause(s).

 

because replacing these with lightweight parts reduces rotational mass, it helps the engine increase rpms faster for better throttle response.

 

Good to know there might be a fix, as this is a common complaint in many cars with ETC.

 

The problems they are experiencing with the "drive-by-wire" system are because the actual throttle mounted to the intake manifold is not moving at the same time as their foot. You might mat the gas, but the system does not open the throttle as quickly, or as soon, as you hit it.

Your solution will not help this problem. You could take the pulleys off, make the engine internals out of forged titanium alloy, and remove the rest of the drivetrain (clutch, flywheel, etc) and it would not help. If the throttle blade on the engine does not move, the engine will not spin up.

Lighter rotating pieces will just help the engine spin up ONCE THE THROTTLE RESPONDS.

 

so, bigfieroman, is the only solution reprogramming the computer that controls the acceleration then?

 

I dunno, it could be a progamming issue, it could be a calibration thing, or it could be faulty parts. I just know that the pulleys won't help.

 

Yeah there is a delay because the engine is trying to operate smoothly to maintain clean emissions and proper air fuel ratios. In a way it is nice that is smooths out a nervous gas foot - I have a friend with a Prius that drives the onboard computer crazy with throttle and regen. You may find better response at a higher rpm but other than that it is just a build in delay you have to live with. I have heard that some tC owners put in grounding kits for the battery and it improved throttle response. The 1st gen xB engines are throttle by cable but also have a bit of a delay from the fuel injection system and you can drive it crazy if you pump the gas really fast too or dump the clutch too quick and drop engine rpm.

 

Just hit the gas a 1/2 second sooner and it will take off normal. Just kidding as stated above it is all do to the drive by wire system. With a manual trans it is not really noticed at all and under normal driving with a auto it is not really noticed only when you mash the gas does one notice the slight lag. Fix at this time is no where in sight