Throttle body butterfly valve not fully opening

[mikfly]

While replacing the radiator on my 2001 LC, I noticed that the butterfly valve Inside the throttle body does not open at all until the accelerator pedal is almost fully depressed. There is a large amount of slack between the rotary mechanism that connects the throttle cable to the butterfly valve. Not the cable itself, it is fairly taut. And then at full throttle the valve is only open some small % of the full open.

I took it apart to have a look and nothing appears to be broken or worn. Everything looks to be in good condition and also not obvious how it would be adjusted otherwise. (There is a threaded stop on the bottom of the throttle body that would limit how far the valve could open, but doesn’t seem to be playing a role here). Just doesn’t make sense to me why it would be like that to begin with. Can someone help me understand if there is a problem with my throttle body assembly or if I just don’t understand how these things work?

It does drive okay but a little sluggish? This is my first LC so not sure what normal feels like.


Video linked below

 

[Raymond525]

Mine does the same thing. I haven't dug into this either to know if it is standard or not.

 

[BamaHoo]

Someone with more experience may chime in, but my understanding is that despite the mechanical action of the throttle lever assembly that suggests the entire system is mechanical, it's actually moving a sensor that then sends a signal to a motor that opens the butterfly valve. The last bit of movement (when you floor it, for example) is, however, mechanical, which is what you're seeing here.