I am a driver who practices "the egg between your foot and the accelerator pedal" for economy. I've had my 2003 RX300 for a few years now (70K miles)and I frequently get an instantaneous surge no matter how gently I press the accelerator. It has always done this since I bought it used, new dealer certified whatever at 27K miles. My other car, a 2006 Toyota Camry (purchased new) has the same characteristic, only more pronounced. It seems that there is a specific pedal pressure resistance that must be overcome to accelerate. Once that pressure threshold is met, the pedal resistance "releases" and accelerates according to the extra pressure applied to overcome the resistance. No matter how slowly and evenly I press the accelerator I frequently get this unwanted neck jerking result. I have pretty much "tamed" the RX300. but every time I drive the Camry, my wife thinks I am a teenager trying to burn rubber. Is this a normal characteristic in the RX and the Camry? Has anyone else experienced this?

 

try lubing where your throttle springs are with silicone spray.It could also be your throttle plates sticking. Take off intake hoses,and clean in their real good.Their is a sticky on here on how to do that.

 

I have noticed this on my RX as well, not so much on the GS.

 

You can increase the tension on the accelerator pedal by moving these two 10mm bolts to the left holding the accelerator cable.

 

Thanks for the response Lexmex
I'll give it a try. My more pressing task is getting my RX300 door opener actuator motor replaced. I am having difficulty trying to determine the correct replacement motor. There are numerous posts for a Mabuchi P/N but for the GS series. I'd like some confirmation of the interchangeability for my RX. I am hanging loose on that one with my door panel open.

 

I have no idea on this one as I haven't run into the issue yet.

 

DrDan- Do you have any idea if your '03 RX is a drive-by-wire? My wife has an'02 Camry that we bought new and it is DBW. I can't imagine that Camry was DBW in '02 and the RX wouldn't be in '03. I'm betting that both of them are DBW in which case I think your answer is to have them reflashed by Toyota or Lexus because that (sensitivity) is computer controlled. I know neither my wife's Camry or my '04 Ford F-150 are sensitive at all and they're both DBW as are most cars today. It COULD be something sticking but I'm still betting computer (or the potensiometer), which is what picks up the signal at your throttle pedal. POSSIBLE that it is sticking on the receiving end (the throttle blade) which is operated by the motor that gets it's signal from the potensiometer. But it would have to be a lot dirtier and gummed up than I would ever expect it to be.

 

Ya know, my socks fell off. I have always worked on my cars since I was a teenager. It is only in the last few years I failed to keep up with the nitty gritty of technology. I get involved when I feel I am getting ripped off. Then I revert back to my self survival skills. I never assumed a FBW system. I had my wife pump the gas pedal and I could not see anything moving. So, I called the dealer and lo and behold, he said "Bring it in" (of course). The way he answered my question leads me to believe it is a FBW. But then again so was the Airbus A-320 that went for a swim in the Hudson River. Thanks for the hints and tips and responses. I will do a little more investigating.

 

DrDan- it's easy to check but I'm almost certain it is. Just knell down an look to see if there is a cable attached to the throttle pedal. I'm betting all you see are wires. It's also easy to see if there is throttle cable under the hood. I don't know if the engine has to be running for the FBW to operate the servo motor on the throttle body if the key is on, but I'm betting it does. You could have your wife turn the key on and you could watch to see if the motor operates on the throttle body as she presses the accelerator down. (NOT running of course) That way you could tell if there is jerkyness in the operation of that end of the system. She would need to just slowly press the accelerator down as though she were accelerating normally. It could be on either end of the FBW or in the computer flashing. It's really strange that both of your cars do it though.

 

Thanks for the response Code 58. I drove a Mercedes 300SD for almost 200K miles. The only way to make that 5000 pound car move was to floor it every time. Aha he says, "you MB driving habits are still with you." But, since I haven't driven it in about 3 years (it is sitting on my driveway waiting for someone to "pry it out of my dead, cold fingers") I have broken myself of the habit. I very consciously do the egg on the gas pedal technique and it still spurts in acceleration--just momentarily and then it behaves normally. I will follow your suggestions this weekend. In the meantime, my upright freezer just blew its cool in the garage and that is a more pressing problem at the moment.

 

The RX300 is not electronic like the 330's or 350's, all old-fashioned wire from 99-2003

 

Yep, here we go.

 

And closer in on the right side of the previous photo.

 

A little further up from the previous photo we find the cord.

 

And comes out to the engine bay through the firewall here and then over the to the throttle butterflies as shown in the first picture in this thread.