I've had 4 differant mechanics look at my truck and none of them can figure anything out! So here we go:
1989 Toyota 4runner; 22re; 230,000 miles

I recently took the air plentium and the throttle body off. The throttle was sticking and upon investigation I noticed a massive amount of "gunk" build up. NE ways the truck has not ran right since. I can't drive the truck or anything ne more. It will only go 45mph. I have to shift way early in every gear and if I don't it will immediately go to surging (rev's up) It seems like once it gets to a certain rpm it does this. I've replaced the mass air flow meter and the throttle position sensor. The diagnostic is still saying the "tps" but it's brand new. I haven't been able to drive it for about a month now and need some MAJOR help!!!

 

Just cuz it's new don't mean it's good. Check the TPS.
http://www.4crawler.com/4x4/CheapTricks/TPS/index.shtml

 

Check engine light codes?

 

Gunk build up in the plenum is totally normal.
Check out the tuning issues as these guys have suggested - esp 4crawlers page. If you can do it yourself, that'd be helpful... Unless the mechanics actually worked on it - meaing tested the electronics, they're going to remain baffled.

 

Yeah, check the TPS adjustment with a digital multimeter. ALSO, check to see if any of the wires to the TPS are cracked. That will throw the same code..... obviously.