... when it comes to corrosion, be it at least between throttle plates and bores, or at worst between throttle shafts and bores, trust me, the first plan of attack should be with a 50/50 mix of vinegar and distilled water to eliminate the corrosion/rust, and then when you've established throttle shaft movement, probably something like a good soaking in ATF... and then if there's not excessive throttle shaft play, you should be good to go... otherwise, the whole base plate really should come completely apart and be refurbished, like with new nylon ribbon bushings for the secondary etc...