To note:
After testing for cable movement, don't automatically deem the IMRC or linkage to not be a problem.
the IMRC box may be PULLING the cable, and brass bar (which links one set of secondary plates to the other set), but the bushings that connect the other side of the rod to the secondaries may have disentegrated (common). You will still SEE the bar move, but that bar isn't pulling the plates open as it should. So.. just because the bar is MOVING doesn't MEAN that both sides of the secondary runners are opening up. It just means that the IMRC is trying, and working.
You would still have to verify linkage operation, and movement (no binding closed from carbon, etc..)
I would suggest an intake rebuild if you haven't done so in a while. Then an intake maintenance schedule utilizing Big Jim's "on car" method every 10K miles or so.
During the rebuild you can physically see the state of the plates, carbon buildup and secondary bar/bushings condition.
The rebuild and the maintenance cleaning methods can both be foundin the duratec maintenance forum, in the FAQ, under UIM/LIM
