wrenchtech

I was working my way down the list of stuff to check for a tune-up on my '89 4runner. I was checking the throttle position sensor (TPS) readings when I noticed that the throttle plate was a little too far open at idle. I think the plate should be fully closed with no gap between stop screw and the adjusting stop. I had to back it off a turn or two to get it to that point. Am I right that it should be fully closed and barely resting on the stop screw? -- Matt

PS >When I reset the throttle plate I rechecked the TPS and made the necessary adjustments to get the factory specified ohm readings at the various specified positions of the throttle.

tallbastard

If your throttle body is equipped with a throttle opener, then it is normal for the throttle to be a little open. The throttle opener is designed to hold the throttle open a little bit so when you start your engine you don't need to push down on the gas pedal at all. I forget what years have then and don't. you can find a picture of what it looks like here http://personal.utulsa.edu/~nathan-b...93throttle.pdf in the third picture down (the plunger looking thing that vacuum is being applied to) as well as farther down the page where it tells how to check the operation of the throttle opener.
If you do have a throttle open then your supposed to apply vacuum to it before adjusting the TPS because otherwise it will affect your readings. If you do not have a throttle opener then i would say to check the fsm for your year and see if it mentions where to have the throttle stop screw.

wrenchtech

The '89 4runner FSM section on the throttle body doesn't say anything about a throttle opener. It has a dash pot, but that shouldn't effect the closed position under most circumstances.

The FSM says... "Check Throttle Valve: Check that there is no clearance between the throttle stop screw and the throttle lever when the throttle is fully closed."

I may be being too picky here but I was wondering what you need a throttle stop screw for if the throttle valve has a fully closed position that it hits with out the stop screw. It's slightly vague if you ask me. I think the answer is that you let the throttle fully close on its own and then you bring the screw lightly into contact with the throttle lever and lock it down with the lock nut. I just wanted to see if other people are understanding the same way. -- Matt


that the throttle should be fully closed when it's resting