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]

No rattling around the cat, I've actually banged around under there before. I even had the exhaust looked at like 2 days after I got the car in July because of a thumping sound... it's suspension related. Exhaust looked great.

No CEL, plus it's a 94 so it's OBD 1 which means DIY paper clip and a printout of CEL codes

Plug wires look fine, that's why I didn't replace them when I did the cap/rotor/plugs. No burn marks, actually they looked brand new. I do know they were put on in May, before I bought the car. At the time of purchase they had approximately 5k miles on them, so to date they have approx. 15k on them. But the plugs were done at the same time, and replacing them helped although didn't solve it. Wires will be replaced w/next paycheck, on the 5th. This chick is BROKE A$$ and has just enough to get into the car show this weekend!

As for the exhaust manifold, yeah, it's leaky, although I haven't looked to see if it's leaky when the engine is warmed up fully. Will check that hopefully this weekend if it's not raining/snowing/freezing-crap-falling-from-the-sky-ing.

Regardless of what the solution winds up being, I'm still going to try to take the intake manifold apart to clean the cavern out. I can't stand knowing all that build up is there. It's already a 7A engine, it needs all the help it can get!

This post has been edited by GriffGirl: Jan 25, 2008 - 11:52 AM