Engine still lagging/bucking, help! Options

[GriffGirl]

I'm still having weird engine issues. It was bucking really bad until warm up, especially in higher RPMs. I did a tune-up which helped but didn't solve it, engine would still buck while cold at higher RPMs (3000+), and at about 3500+ when warmed up. Fiddled around some more this weekend, resulting in amazing improvement; now instead of bucking, it just kind of feels like it's dragging like a dog scraping its butt on the carpet. Yes, at higher RMPs, and regardless of what gear I'm in. I've done the following thusfar to resolve this issue:

•replaced thermostat
•replaced engine temp sensor
•replaced plugs, cap & rotor, air filter (improvement #1)
•replaced fuel filter
•seafoam gas treatment, seafoam vacuum line (discovered leak in gasket around header pipes)
•removed intake housing, cleaned the hell out of throttle body/plate
•realized that did nothing, REMOVED throttle body, discovered diamond mine in carbon deposits, cleaned thoroughly including all those tiny little vacuum tentacles
•whatever that thing is called (is it just the intake?) that the throttle body is attached to, well I sprayed the HELL out of it and soaked a rag too and did my best to clean it out. It looked like a stalactite cavern. Result was a marked increase in throttle response, made my car feel young again.

But still dragging ass on 3000+ RPMs regardless of gear. What is that thing the throttle body attaches to? Should I attempt to remove the cover from it so I can get rid of the rest of all that carbon build up? Is that my problem? Does anyone have any other ideas? PLEASE?

Thanks...

[GriffGirl]

There's no CEL. I failed to mention I reset the ECU a while back also, just to see if maybe I could "trick" it into doing things my way. No codes have been thrown throughout all this though.

It does it all the time, less-so when it's warmed up, but consistently at 3k+ RPMs. I talked to a Toyota mechanic last night (the guy who hooked me up with my shiny new strut bar! OW!) and he also suggested the plug wires. I think when I get paid again I will buy new wires and see if that helps any.

Any other suggestions as to what else I should check are MOST appreciated! I want this to be the smooth-running powerhouse that she's capable of becoming!

This post has been edited by GriffGirl: Jan 23, 2008 - 11:08 AM