Sticky Accelerator Pedal Is200 Manual When Engine Running

[James33]

Hi,

New forum poster

I drive a 2004 Lexus Is200 manual 67,000km.

A bit of backstory - The car is my father's (he is the second owner of the vehicle since '06) and is entirely stock other than a a few things I have put in recently - Kenwood BT Head Unit, K&N Engine and Cabin Air Filter and I just changed the Engine Oil to Full Synthetic 5w-40 HPR5 Penrite, replaced Engine Oil FIlter with new OEM Denso and 75w-90 Semi Synthetic Gearbox Oil last weekend on a family friends hoist which was a cool experience - Running beautifully now with the oil changed (I don't think it had been serviced in at least 2 years so was definitely in need). The car is in great nick for a vehicle that has lived outside most of its life. It has been the car I learned to drive manual in for the past couple of years and I love it.

When I was on my L's in the early stages of getting the feel for the clutch and accelerator, just moving back and forth in my driveway and blipping the accelerator pedal I noticed there was a bit of slack in the pedal where by nothing would happen when I pressed pedal down for the first part of the travel, then once the pedal started to engage and I felt notchiness / stickiness sensation. So, I adjusted the throttle cable just a little bit to reduce the amount of slack which was successful. There is no longer any excess movement of nothing happening when accelerator pedal is depressed BUT there is still this notchiness / stickiness that is quite bothersome. Ever since I adjusted the throttle cable which was over a year ago now (now on my green P's), I have just put up with this notchiness as it is not a huge issue, it is more a nit pick type of thing. It is hard to pickup the feel of it unless I am quite delicate on the accelerator but I do find it to be a critical part of the accelerator pedals movement - just adding a bit of throttle and then releasing clutch to get going. The notchiness / stickiness is only apparent of the initial part of the pedal movement for 1 or 2 millimeters when the throttle body starts to open and thus increase in revs above idle - after the initial movement the pedal is smooth as butter all the way. Another point I would like to make is when I depress the accelerator pedal with the car off there is no sign of this notchiness / stickiness whatsoever, It is only when the car is on and running. I would love to try and solve it myself if anyone has experienced this type of behavior before in an Is200 or any car for that matter I would greatly appreciate it.

James

[Millerman]

Ok this is quite a topic and i beleive it could be a fault in the throttle body. If you youtube is200 throttle body there is an explination on how it works 

its really weird and doesnt make sense the first time you look lol

Its a combination of electric drive by wire and a mechanical cable drive. Next time your by car get someone to press pedal and watch the throttle body. It wont move. And then do same thing with ign on or running and it works. 

They do it like this to help with warming up the car amongst other things