I hate to ask this, but did you ever get the wiring harness recall done?
If the harness is in deteriorated condition moving it would make it worse.
It sounds to me like your tach is reading high...the rev limiter/fuel cutoff is built into the computer and can't be disabled without a chip.
Might want to connect a shop tachometer and verify that the tach reads correctly.
It also sounds like the engine may be running lean...is the check engine light on?
Brian
