'87 350 TBI 4-spd, no error codes. I seem to have a problem with the engine over-revving until it warms up. If you put the clutch in and rev the engine it takes FOREVER for it to wind back down and actually revs higher between shifts. This is a real problem when driving because I have to shift fast to prevent it from over-reving while switching gears. Could this be an EGR valve problem? The strange thing is that even when I physically pull back the throttle it's still over-reving. Hmm?? Thanks in advance.