I've spent over $1,000 on my 91 4runner with the 3.0 trying to get rid of this sick thing til what I just did. I took the throttle body off for about what seems to be the 1,000th IACV cleaning and this is what I did.

Got a pair of vise grips and gripped the center of the IACV and pulled it out a little. This takes a little muscle and maybe a 2nd party to squirt WD-40 on the valve. Now be careful with the WD-40 because the TPS is still intact and you don't want to contaminate it in any way. After you get maybe a 3 second squirt on it then take the tension off the IACV and rotate it round and round for 2 minutes or so to help loosen whatever is behind it. Reassemble and test.

I've ran mine so far for 10 miles and it seems to purr now. THANK GOD! And after 2 Seafoam treatments this morning and 1 can in the tank I hope to see a little better gas mileage.

Hope this helps someone that is chasing that dream of a smoothe idle and better power.

 

That's interesting! I see so many posts w/3.0's an a rough idle, I never had that w/my beast, just a low idle which I fixed once and for all! I've put around $2000 into mine to get some more power out of her, it was worth it!
Most problems w/a rough idle on the 3.0 are caused by: T-body in need of a cleaning, TPS adj., tune-up, sucking air some where, That god-aweful pcv valve, carbon/gunk on the idle screw an air pocket in the cooling system and of coarse the Idle Air Control Valve. Now That I R & R' ed my 3.0, she screams! Almost like a 3.4 close but not as much!
Good Luck!

 

I bought and adjusted a new TPS, AFM, PCV, grommet and hose, pulled plenum off and cleaned thoroughly, cleaned TB thoroughly, new EGR valve, EGR temp sensor, O2 sensor, Plugs, wires, rotary button and cap, New gas filter on Intake, Temp sensor, cold start time delay switch, vacuum modulator, new hose from throttle body, new radiator, hoses, thermostat, new vacuum lines and a partridge in a pear treeeee!