Wouldjaball

Hi all! I'm about to do my TPS and I've been doing a lot of research here but I have one quick question:

For Test 1 on the 3VZE, the image states the clearance between linkage and Stops Screw should be 0.50mm

HOWEVER

All of the directions I'm seeing to set the throttle screw seem to ignore this stated .50mm gap for test 1: You must adjust the throttle stop screw before you attempt to adjust the TPS.

1. 1. Loosen the jam nut and unscrew the throttle stop screw all the way so that the throttle blade closes fully against the throttle body itself.
   
   2. Turn the stop screw back in until it just touches the linkage, then turn in ¼ turn more. This extra ¼ turn keeps the throttle blade from sticking against the inner bore of the throttle body.
   
   3. Tighten the jam nut while holding the stop screw in place to prevent it from moving.

So the million dollar question is should the stop screw be turned 1/4 past touching on a 3vze? Or should the 0.50mm feeler gauge be in when setting the throttle screw?

Any advise would be greatly appreciated!


PS. The reason I'm tackling this myself is the dealership quoted $525 to calibrate the TPS.... Seriously!?

DonutLimo

The TPS doesn't care how close or not the plate is to closing. So start by adjusting the throttle plate as stated with the stop screw and lock nut. Don't confuse the stop screw with the dashpot (if you have one).
Now minutely adjust the TPS to spec since your throttle plate "closed" stop is set properly.
The stealership is always there to take your money.

scope103

DonutLimo is correct about the setting of the stop screw.

People get freaked out about adjusting the TPS, but the basic concept is quite simple. IDL-E2 is closed at idle, open when not at idle. But wait; how close to "idle"? Within 0.50mm is considered at "idle." But wait, what is "closed"? Anything less than 2.3kohms, is closed, greater than that (including infinite) is open. That's all there is to it.

Wouldjaball

Gorcha, So if I understand correctly then... Adjust the stop screw, and then on Test 1 insert the correct feeler gauge and measure?

I do have a dash pot, any advice on setting that? best I can see is:

1. Adjust the dash pot by setting the plunger so that it first makes contact with the throttle linkage about halfway back from wide open throttle. If set too deep you will have more spring force to overcome and that can cause the throttle to not fully close. Too shallow and the dash pot will not slow the linkage down properly.

Thanks for all the help!

DonutLimo

Yep make sure you do steps 1, 2 & 3 then recheck each one after tightening the TPS. The TPS can be a very subtle adjustment.

The dashpot is an emissions thing so not much in making the truck run better. I think the important wording there is to make sure the throttle fully closes with ease after adjusting, ie too shallow is better than too deep.