fast/high idle problem solved
 

I recently bought a 90 4runner with a bad rearend. After fixing everything else, the 3vze idled very high. Around 1800rpm's. I did not have to do anything to the engine, it was like this when I bought it. Initially, I cleaned the throttle body and I retarded the timing, which brought the idle down, but no power. The butterfly was closing properly. I checked/changed the timing belt and verified the timing was correct. With the timing set correctly, the idle speed was around 1800 rpm's again... Checked and swapped out the AFM and TPS, as I had CEL on with codes 41 and 43. 41 showing TPS issues?? Only after changing the throttle body was I able to get the idle down and the engine running properly.... Which leads me to my question.. What in the throttle body would cause a high idle? Just curious........

A stuck open/malfunctioning IACV(Idle Air Control Valve), or the idle speed adjusting screw o-ring. Or both of those things combined.

Which leads me to my questions. What did you do with your old TB? & Is/was it one of the POS cruise control or auto trans w/ the vacuum-actuated throttle opener type? & Can I have it(if it's non-CC/non-VATO)?

I seriously need to replace the cruise control TB on my 90. Man these things are a fricken joke. And NOT a funny one. Who the hell wants cruise control on a 4WD stick shift anyway? What on Earth were they thinking when they started doing that nonsense?

It has Cruise Control. Cable operated, not vacuum operated. Before I discard it, I would really like to know what went wrong with it to cause my problem. A stuck open IACV would not be fixed by replacing the throttle body and I replaced the O-ring on the idle adjustment screw.

How not?

Are you saying that you've inspected the IACV in it, and confirmed it wasn't faulty?

Probably could have saved some money by simply cleaning out all the passages in your Throttle Body with qtips and solvent.

Soaked the throtle body in solvent and cleaned EVRYTHING on it. Unless I am mistaken, the IACV is not on the throttle body, but located under the intake manifold on the right side of the motor.

You're mistaken on everything you've stated there.

First, the IACV(sometimes refered to as the Auxiliary Air Valve) is integral to the throttle body, not "on" it. It's part of it(resides within it). And it's why there's coolant lines running to and from the TB. What did you think the purpose of those was?

Next, there's nothing under the intake manifold except the knock sensor, and the No. 1 water by-pass pipe. You might be thinking of the A/C idle up valve, which is located to the right of the engine(but it's not under anything, or even on the engine, let alone under the intake manifold).

How about just taking my word for it on this? I do tend to know what I'm talking about when it comes to this engine. And I've already given you all the info you need to figure out what the problem was with the TB.

Isn't this different for certain years of trucks? I've heard that some do not have the IAC integrated into the TB. I know mine does and by the sounds of it so does yours. I'm just interested if it is always the case or if wherever I read that the person didn't know their elbow from their asshole.

No. Not if we're talking about a 3VZ-E. If we're talking about a 22R-E, then yes.

Ahhhh gotcha. Thanks

if you never figured out the cause of the 41 code, it could have been an adjustment on the tps problem.

the long shot might be something as simple as worn bushings on the throttle shaft... we used to see that on performance carbs, especially when you put boost through 'em :bounce: raw fuel leaking out the shaft.

I sprayed/clean the whole thing, no change. No fuel came out of the thottle body under acceleration. Just thought I would try to figger it out. The "nrew" throttle body is working like it should, Problem solved...

that makes sense, because the fuel goes in underneath the throttle plate, on efi... on a carb, the fuel goes in above the throttle plate.

thanks for letting us know the fix, I wonder if bushing wear was indeed the problem with the old tb.