rought idle

I got stuck in the mud really bad,while trying to get unstuck,I reved my truck up really high while rocking back and forth for about 3 minutes,after I got out of being stuck my truck would idle but as soon as I tried to accelarate it would stall,after 10 minutes of feathering the gas peddle to get off the trail it will accelerat but won`t idle ,I turned up the idle screw , and it stays idleing but drops almost to a stall and picks up ,I`ve changed the plugs,fuel filter,checked each wire for spark and there good,the motor is a 2.4 4 cyl in a 87 toyota 4x4 regular cab...anyone expirence this problem and find a solution??

i have an 87 2wd and it is doing the same thing yours is doing. the other day i just revved my engine, not to high at all, and mine hasn't idled well since. i replaced plugs, wires, checked the rotor, and looked for unhooked vaccum lines but to no success. its driving me crazy so if anyone has any ideas, i'd like to know.

i've had the same problem with my 91', it has been suggested that my throttle positioning sensor is going, but at $500 it seems a little iffy. i'd like to hear if some one solves this issue.

I've got the same problem with my 1991 SR5 Xtra 4x4, only not with the mud and all. It happened to me doing some big donuts in the snow or just generally reving it really high quickly. As soon as it comes back down it seems to sit real low about 500 like you said and just drop and go up a bit then drop. it'll hang around there a then stall out if i leave it without just giving it a sustainted 1,000 or 1,500 rpm throttle.

My guess is the TPS - throttle position sensor!

I had the same symptoms as described above on my 93. Neighbor friend is a mechanic and he replaced the TPS and it ran like new after.