Q45 Throttle Screw

[supraguy31]

so I Started my car up today after installing my FFIM and Q45 Throttle body. When it started the Idle was really high and took a very long time before it even wanted to Idle down (like 5 minutes or so)

I know that there is an Idle Screw on there somewhere but I havent been able to find it. Does anyone know where the Idle Adjustment Screw is on a Q45 Throttle body.

thanks
Robert

 

[gaboonviper85]

There isn't one....most modern cars use an electronic valve to adjust idle.

 

[supraguy31]

Ah, ok so why is it that its Idling up so high at startup and not settling down any at all until roughly 4 to 5 minutes. Im sure there is a way to Adjust something somewhere.

Robert

 

[rayall01]

Cold start injector, perhaps? A Supra is designed to idle around 1400 rpm on cold start, and will do so for a few minutes until it gets warm enough to run normally.

 

[adampecush]

Are you running coolant through the TB? There is a waxstat on the throttle body that opens the throttle plate until the engine reaches temperature. You need to remove the linkage that attaches to this if you are not running coolant lines and/or you are running the supra ISC valve.

If your throttle plate is open too wide, the ISC valve cannot bring the idle down any further.

 

[adampecush]

There isn't one....most modern cars use an electronic valve to adjust idle.

Wrong. There certainly is a screw on the Q45 TB that adjusts the opening of the throttle plate.

 

[supraguy31]

Are you running coolant through the TB? There is a waxstat on the throttle body that opens the throttle plate until the engine reaches temperature. You need to remove the linkage that attaches to this if you are not running coolant lines and/or you are running the supra ISC valve.

If your throttle plate is open too wide, the ISC valve cannot bring the idle down any further.

Yes, I am running coolant lines from the ISC to the Throttle body and then back around to the Line under the Lower intake. Since the Stock throttle body was run that was and Im running a ISC I thought it had to be the same. If there is a better way by all means let me know.

 

[adampecush]

you need to disable/adjust whatever it is that the waxstat pushes on to move the throttle linkage (there is an adjustment screw - it is painted white in this picture). That cylindrical thing parallel to the tb bore is the waxstat - you can follow the coolant lines to it.

keep the coolant lines hooked up, just disable the waxstat operation, and you should be golden.

 

[supraguy31]

Ok, I got the throttle Adjustment screw. Thanks for that Picture, Now I need to figure out how to Disable the other thing that you are talking about.

Started the car up a little while ago and the Idle at Initial startup jumps up to around 2400rpms and sits there. This is just a reference for you all.

 

[adampecush]

if i remember correctly, I just cut off the tab that it interferes with or removed the arm all together. I can double check tonight.

i've got a few pictures in my build thread about my TB modification...although I couldn't tell you where they are as photos are blocked at work...should be on the last couple of pages.

 

[supraguy31]

Page 33 I think of your Build thread has a Q45. I see the Huge Spring Assemble on mind that yours doesnt have right below the Throttle cable linkage.

Would this Picture be the one that you are referring too.....

I will take a Pic of mine as soon as I get home and I will add it to this Post. Let me know what I need to remove to solve this.

Thanks again.
Robert

 

[supraguy31]

got it.....

I removed the Assembly that Keeps the throttle linkage up and the Idle Dropped instantly. All I need to do not is remove the Small rod that you were talking about.

Thanks alot all, Idle is around 700rpm once the engine has warmed up.

Robert