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Throttle Response!!!

5.2K views 12 replies 9 participants last post by  the wrong tone  
#1 ·
I have a 02 5 speed MSM IS300 with 93,000 miles on it and can not seem to drive it smooth. I have owned the car about 3 months and have completed the 90k service with all lexus parts. I have owned multiple 5 and 6 speed cars, but this is the first with the drive by wire throttle. Is there any way to make the throttle more resonsive other than removing the DBW and having a check engine light??
 
#3 ·
There's a thread around here about the TDD mod...

If you're too lazy to search, here is the short version. If you look at your gas pedal, towards the top, you'll see where the throttle cable connects to the pedal assembly. You'll notice that the cable isn't directly connected, but is connected through a spring. The spring is there to dampen vibrations from the engine to the pedal. When you press the pedal, you'll notice that the spring compresses a good amount before the cable even begins to move. You'll also notice that the relationship between the cable moving and the pedal moving is non-linear which makes throttle control really vague.

All you have to do, is use something like a zip tie to wrap around the spring to keep it from compressing. This will make a solid connection and 100 times better throttle feel/response.

hope that helps
 
#4 ·
Here it is its on the first page of the post. I hope this helps....
TCS/TDD Mod......
 
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#6 ·
Do the mod, the car will feel a hell of alot better. I don't know why they aren't like that stock.
 
#9 ·
O.K. throttle response was awesome this morning, but not so good this afternoon. Any reason why? I have checked al the basic stuff and everything is working as it is supposed to. Maybe I am still driving the car like it has tons of "SLACK" in the pedal.
 
#10 ·
Just the typical DBW system. Itll take some time to get used to it. I am all for the traditional throttle cable though.
 
#12 ·
I made a few adjustments recently that made a noticable improvement. Note my car already has the TDD mod.

1. Remove slack from the throttle cable. My threaded adjustments were already max out and it still wasn't as tight, so I have to unbolt the bracket (that holds the adjusters) and since there is a some play, I nudged the bracket further away from the throttle body, and tightend it down, hence tightening up the cable. I adjusted it now such that it has very minimal slack.

2. Tweak the TPS sensor. Loose the 2 screws and turn it very so slightly clockwise. You do not want to turn too much or you will get either CEL or erratic idle. If this occurs, just turn the TPS sensor back. Indexing it clockwise fools the ECU to think that the throttle is less open that it actually is. Hence it would command the throttle to open more when you touch the gas pedal.