I recently rebuilt my wife's 4runner engine (22RE with EB's 268 cam)and I am wondering what the FSM suggests as the procedure for seting up the idle with the Idle screw, the AC amplifier, and the idle up valve on the plenum for the PS. I need to raise the cold idle a little and then sometimes the idle goes up to 1000 rpms but usually is at 750-800 rpms. It is a manual tranny. How do you guys do it?
I keep messing with it and when I get the idle set good when it is warm, it will then idle too low at start up. I cleaned the entire intake and throttle body when I rebuilt it and have since swapped out the TPS and cleaned the white idle up valve on the plenum.
Thanks
Jeff S.

Cold idle is primarily controlled by the big air valve down below the throttle body on the early engines. Make sure that part is all working correctly. Or swap to a later style throttle body with the integrated air bypass valve.

I would still like to know if there is a certain procedure for setting them up, like when do you know which to raise, the ac amplifier idle or the white knob? Or is the white knob supposed to be just for the power steering? I have not been able to find any info in my manuals for any procedure.
Thanks
Jeff S.

The idle up valve does just that, boosts the idle speed when the A/C is on or the power steering is used at idle. You set the idle speed (under load) per the FSM specs. I think it is something like 1000 RPM, with either the A/C running or when you crank the steering wheel while stopped. Exact speed is really not important, you just want to avoid bogging the engine down.

The A/C Amplifier sets the low cutout speed of the A/C, so you want it's RPM setting somewhat below the normal idle RPM. The A/C Amp cuts the A/C off if the idle speed drops too low. If you set the RPM too high, the A/C will not kick in properly.

So in short, idle up RPM a little faster than normal idle speed, A/C Amp RPM a little lower than normal idle speed. And neither of the above settings have any effect on normal idle operation of the engine. They only come into play when the A/C or P/S is in use at idle. The FSM does cover all this, but you need to look in all the appropriate sections. That is the normal idle is covered in the EFI section, the A/C idle part is covered in the A/C section and the P/S idle up is covered in the P/S section.

I recently had to get a new airbox for my truck. The Airbox I got at the boneyard didn't look exactly like the one I was replacing. It seems to work ok but my idle has been screwy ever since. Are MAF sensors from older years interchangable?

Scott