| Before reading John's throttle body adjustment writeup, I tried my best to set my throttle bodies by sight. Then I set the throttle bodies again with John's write-up and wound up with a high idle. I didn't realize one very important detail until I spent considerable time adjusting the throttle bodies. You can adjust the throttle body stop points, the synchronization of the throttle bodies, and finally the return pressure! Return pressure can be adjusted with the driver side sync adjustment screw. Turning the screw clockwise allows more return force on the PS throttle body and turning counter clockwise allows the DS throttle body more return force. I believe the effect works both ways on each TB. This phenomenon is caused by the small springs that suspend the center linkage blades on both sides. I realized that you cannot set the throttle body stop point independently of the return pressure and sync. If the return force differs too much between both throttle bodies, you should adjust the individual stop screws. Further, you can know with certainty that both throttle bodies are synced by fine-tuning the return force by means of the linkage sync adjustment screw. Aim for a balance of throttle body return forces. First, I set the stop points for each throttle body independently. I screwed in the stop screws until the throttle bodies were completely closed. Then, I unscrewed the stop screws 1/2 a turn to offset the butterflies. Finally, I equalized the return forces of the TBs precisely by turning the sync screw clockwise to increase pressure on the PS TB and turning it counter-clockwise to decrease pressure on the PS TB. To test this method, both TB's were perfectly balanced even after pulling on the throttle cable. Now, performance is excellent and my engine RPMs drop straight to idle speed after depressing the clutch. Before, it would take several seconds for the RPMs to settle down to 750 rpm. I discovered the the return force on my PS TB was much too low before the adjustment. P.S. I noticed an error in John's write-up. The PS throttle body stop screw cannot be adjusted.
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